library/core/src/net/ip_addr.rs

   1 use crate::cmp::Ordering;
   2 use crate::fmt::{self, Write};
   3 use crate::iter;
   4 use crate::mem::transmute;
   5 use crate::ops::{BitAnd, BitAndAssign, BitOr, BitOrAssign, Not};
   6
   7 use super::display_buffer::DisplayBuffer;
   8
   9 /// An IP address, either IPv4 or IPv6.
  10 ///
  11 /// This enum can contain either an [`Ipv4Addr`] or an [`Ipv6Addr`], see their
  12 /// respective documentation for more details.
  13 ///
  14 /// # Examples
  15 ///
  16 /// ```
  17 /// use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
  18 ///
  19 /// let localhost_v4 = IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1));
  20 /// let localhost_v6 = IpAddr::V6(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1));
  21 ///
  22 /// assert_eq!("127.0.0.1".parse(), Ok(localhost_v4));
  23 /// assert_eq!("::1".parse(), Ok(localhost_v6));
  24 ///
  25 /// assert_eq!(localhost_v4.is_ipv6(), false);
  26 /// assert_eq!(localhost_v4.is_ipv4(), true);
  27 /// ```
  28 #[cfg_attr(not(test), rustc_diagnostic_item = "IpAddr")]
  29 #[stable(feature = "ip_addr", since = "1.7.0")]
  30 #[derive(Copy, Clone, Eq, PartialEq, Hash, PartialOrd, Ord)]
  31 pub enum IpAddr {
  32     /// An IPv4 address.
  33     #[stable(feature = "ip_addr", since = "1.7.0")]
  34     V4(#[stable(feature = "ip_addr", since = "1.7.0")] Ipv4Addr),
  35     /// An IPv6 address.
  36     #[stable(feature = "ip_addr", since = "1.7.0")]
  37     V6(#[stable(feature = "ip_addr", since = "1.7.0")] Ipv6Addr),
  38 }
  39
  40 /// An IPv4 address.
  41 ///
  42 /// IPv4 addresses are defined as 32-bit integers in [IETF RFC 791].
  43 /// They are usually represented as four octets.
  44 ///
  45 /// See [`IpAddr`] for a type encompassing both IPv4 and IPv6 addresses.
  46 ///
  47 /// [IETF RFC 791]: https://tools.ietf.org/html/rfc791
  48 ///
  49 /// # Textual representation
  50 ///
  51 /// `Ipv4Addr` provides a [`FromStr`] implementation. The four octets are in decimal
  52 /// notation, divided by `.` (this is called "dot-decimal notation").
  53 /// Notably, octal numbers (which are indicated with a leading `0`) and hexadecimal numbers (which
  54 /// are indicated with a leading `0x`) are not allowed per [IETF RFC 6943].
  55 ///
  56 /// [IETF RFC 6943]: https://tools.ietf.org/html/rfc6943#section-3.1.1
  57 /// [`FromStr`]: crate::str::FromStr
  58 ///
  59 /// # Examples
  60 ///
  61 /// ```
  62 /// use std::net::Ipv4Addr;
  63 ///
  64 /// let localhost = Ipv4Addr::new(127, 0, 0, 1);
  65 /// assert_eq!("127.0.0.1".parse(), Ok(localhost));
  66 /// assert_eq!(localhost.is_loopback(), true);
  67 /// assert!("012.004.002.000".parse::<Ipv4Addr>().is_err()); // all octets are in octal
  68 /// assert!("0000000.0.0.0".parse::<Ipv4Addr>().is_err()); // first octet is a zero in octal
  69 /// assert!("0xcb.0x0.0x71.0x00".parse::<Ipv4Addr>().is_err()); // all octets are in hex
  70 /// ```
  71 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
  72 #[stable(feature = "rust1", since = "1.0.0")]
  73 pub struct Ipv4Addr {
  74     octets: [u8; 4],
  75 }
  76
  77 /// An IPv6 address.
  78 ///
  79 /// IPv6 addresses are defined as 128-bit integers in [IETF RFC 4291].
  80 /// They are usually represented as eight 16-bit segments.
  81 ///
  82 /// [IETF RFC 4291]: https://tools.ietf.org/html/rfc4291
  83 ///
  84 /// # Embedding IPv4 Addresses
  85 ///
  86 /// See [`IpAddr`] for a type encompassing both IPv4 and IPv6 addresses.
  87 ///
  88 /// To assist in the transition from IPv4 to IPv6 two types of IPv6 addresses that embed an IPv4 address were defined:
  89 /// IPv4-compatible and IPv4-mapped addresses. Of these IPv4-compatible addresses have been officially deprecated.
  90 ///
  91 /// Both types of addresses are not assigned any special meaning by this implementation,
  92 /// other than what the relevant standards prescribe. This means that an address like `::ffff:127.0.0.1`,
  93 /// while representing an IPv4 loopback address, is not itself an IPv6 loopback address; only `::1` is.
  94 /// To handle these so called "IPv4-in-IPv6" addresses, they have to first be converted to their canonical IPv4 address.
  95 ///
  96 /// ### IPv4-Compatible IPv6 Addresses
  97 ///
  98 /// IPv4-compatible IPv6 addresses are defined in [IETF RFC 4291 Section 2.5.5.1], and have been officially deprecated.
  99 /// The RFC describes the format of an "IPv4-Compatible IPv6 address" as follows:
 100 ///
 101 /// ```text
 102 /// |                80 bits               | 16 |      32 bits        |
 103 /// +--------------------------------------+--------------------------+
 104 /// |0000..............................0000|0000|    IPv4 address     |
 105 /// +--------------------------------------+----+---------------------+
 106 /// ```
 107 /// So `::a.b.c.d` would be an IPv4-compatible IPv6 address representing the IPv4 address `a.b.c.d`.
 108 ///
 109 /// To convert from an IPv4 address to an IPv4-compatible IPv6 address, use [`Ipv4Addr::to_ipv6_compatible`].
 110 /// Use [`Ipv6Addr::to_ipv4`] to convert an IPv4-compatible IPv6 address to the canonical IPv4 address.
 111 ///
 112 /// [IETF RFC 4291 Section 2.5.5.1]: https://datatracker.ietf.org/doc/html/rfc4291#section-2.5.5.1
 113 ///
 114 /// ### IPv4-Mapped IPv6 Addresses
 115 ///
 116 /// IPv4-mapped IPv6 addresses are defined in [IETF RFC 4291 Section 2.5.5.2].
 117 /// The RFC describes the format of an "IPv4-Mapped IPv6 address" as follows:
 118 ///
 119 /// ```text
 120 /// |                80 bits               | 16 |      32 bits        |
 121 /// +--------------------------------------+--------------------------+
 122 /// |0000..............................0000|FFFF|    IPv4 address     |
 123 /// +--------------------------------------+----+---------------------+
 124 /// ```
 125 /// So `::ffff:a.b.c.d` would be an IPv4-mapped IPv6 address representing the IPv4 address `a.b.c.d`.
 126 ///
 127 /// To convert from an IPv4 address to an IPv4-mapped IPv6 address, use [`Ipv4Addr::to_ipv6_mapped`].
 128 /// Use [`Ipv6Addr::to_ipv4`] to convert an IPv4-mapped IPv6 address to the canonical IPv4 address.
 129 /// Note that this will also convert the IPv6 loopback address `::1` to `0.0.0.1`. Use
 130 /// [`Ipv6Addr::to_ipv4_mapped`] to avoid this.
 131 ///
 132 /// [IETF RFC 4291 Section 2.5.5.2]: https://datatracker.ietf.org/doc/html/rfc4291#section-2.5.5.2
 133 ///
 134 /// # Textual representation
 135 ///
 136 /// `Ipv6Addr` provides a [`FromStr`] implementation. There are many ways to represent
 137 /// an IPv6 address in text, but in general, each segments is written in hexadecimal
 138 /// notation, and segments are separated by `:`. For more information, see
 139 /// [IETF RFC 5952].
 140 ///
 141 /// [`FromStr`]: crate::str::FromStr
 142 /// [IETF RFC 5952]: https://tools.ietf.org/html/rfc5952
 143 ///
 144 /// # Examples
 145 ///
 146 /// ```
 147 /// use std::net::Ipv6Addr;
 148 ///
 149 /// let localhost = Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1);
 150 /// assert_eq!("::1".parse(), Ok(localhost));
 151 /// assert_eq!(localhost.is_loopback(), true);
 152 /// ```
 153 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
 154 #[stable(feature = "rust1", since = "1.0.0")]
 155 pub struct Ipv6Addr {
 156     octets: [u8; 16],
 157 }
 158
 159 /// Scope of an [IPv6 multicast address] as defined in [IETF RFC 7346 section 2].
 160 ///
 161 /// # Stability Guarantees
 162 ///
 163 /// Not all possible values for a multicast scope have been assigned.
 164 /// Future RFCs may introduce new scopes, which will be added as variants to this enum;
 165 /// because of this the enum is marked as `#[non_exhaustive]`.
 166 ///
 167 /// # Examples
 168 /// ```
 169 /// #![feature(ip)]
 170 ///
 171 /// use std::net::Ipv6Addr;
 172 /// use std::net::Ipv6MulticastScope::*;
 173 ///
 174 /// // An IPv6 multicast address with global scope (`ff0e::`).
 175 /// let address = Ipv6Addr::new(0xff0e, 0, 0, 0, 0, 0, 0, 0);
 176 ///
 177 /// // Will print "Global scope".
 178 /// match address.multicast_scope() {
 179 ///     Some(InterfaceLocal) => println!("Interface-Local scope"),
 180 ///     Some(LinkLocal) => println!("Link-Local scope"),
 181 ///     Some(RealmLocal) => println!("Realm-Local scope"),
 182 ///     Some(AdminLocal) => println!("Admin-Local scope"),
 183 ///     Some(SiteLocal) => println!("Site-Local scope"),
 184 ///     Some(OrganizationLocal) => println!("Organization-Local scope"),
 185 ///     Some(Global) => println!("Global scope"),
 186 ///     Some(_) => println!("Unknown scope"),
 187 ///     None => println!("Not a multicast address!")
 188 /// }
 189 ///
 190 /// ```
 191 ///
 192 /// [IPv6 multicast address]: Ipv6Addr
 193 /// [IETF RFC 7346 section 2]: https://tools.ietf.org/html/rfc7346#section-2
 194 #[derive(Copy, PartialEq, Eq, Clone, Hash, Debug)]
 195 #[unstable(feature = "ip", issue = "27709")]
 196 #[non_exhaustive]
 197 pub enum Ipv6MulticastScope {
 198     /// Interface-Local scope.
 199     InterfaceLocal,
 200     /// Link-Local scope.
 201     LinkLocal,
 202     /// Realm-Local scope.
 203     RealmLocal,
 204     /// Admin-Local scope.
 205     AdminLocal,
 206     /// Site-Local scope.
 207     SiteLocal,
 208     /// Organization-Local scope.
 209     OrganizationLocal,
 210     /// Global scope.
 211     Global,
 212 }
 213
 214 impl IpAddr {
 215     /// Returns [`true`] for the special 'unspecified' address.
 216     ///
 217     /// See the documentation for [`Ipv4Addr::is_unspecified()`] and
 218     /// [`Ipv6Addr::is_unspecified()`] for more details.
 219     ///
 220     /// # Examples
 221     ///
 222     /// ```
 223     /// use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
 224     ///
 225     /// assert_eq!(IpAddr::V4(Ipv4Addr::new(0, 0, 0, 0)).is_unspecified(), true);
 226     /// assert_eq!(IpAddr::V6(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 0)).is_unspecified(), true);
 227     /// ```
 228     #[rustc_const_stable(feature = "const_ip_50", since = "1.50.0")]
 229     #[stable(feature = "ip_shared", since = "1.12.0")]
 230     #[must_use]
 231     #[inline]
 232     pub const fn is_unspecified(&self) -> bool {
 233         match self {
 234             IpAddr::V4(ip) => ip.is_unspecified(),
 235             IpAddr::V6(ip) => ip.is_unspecified(),
 236         }
 237     }
 238
 239     /// Returns [`true`] if this is a loopback address.
 240     ///
 241     /// See the documentation for [`Ipv4Addr::is_loopback()`] and
 242     /// [`Ipv6Addr::is_loopback()`] for more details.
 243     ///
 244     /// # Examples
 245     ///
 246     /// ```
 247     /// use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
 248     ///
 249     /// assert_eq!(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)).is_loopback(), true);
 250     /// assert_eq!(IpAddr::V6(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 0x1)).is_loopback(), true);
 251     /// ```
 252     #[rustc_const_stable(feature = "const_ip_50", since = "1.50.0")]
 253     #[stable(feature = "ip_shared", since = "1.12.0")]
 254     #[must_use]
 255     #[inline]
 256     pub const fn is_loopback(&self) -> bool {
 257         match self {
 258             IpAddr::V4(ip) => ip.is_loopback(),
 259             IpAddr::V6(ip) => ip.is_loopback(),
 260         }
 261     }
 262
 263     /// Returns [`true`] if the address appears to be globally routable.
 264     ///
 265     /// See the documentation for [`Ipv4Addr::is_global()`] and
 266     /// [`Ipv6Addr::is_global()`] for more details.
 267     ///
 268     /// # Examples
 269     ///
 270     /// ```
 271     /// #![feature(ip)]
 272     ///
 273     /// use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
 274     ///
 275     /// assert_eq!(IpAddr::V4(Ipv4Addr::new(80, 9, 12, 3)).is_global(), true);
 276     /// assert_eq!(IpAddr::V6(Ipv6Addr::new(0, 0, 0x1c9, 0, 0, 0xafc8, 0, 0x1)).is_global(), true);
 277     /// ```
 278     #[rustc_const_unstable(feature = "const_ip", issue = "76205")]
 279     #[unstable(feature = "ip", issue = "27709")]
 280     #[must_use]
 281     #[inline]
 282     pub const fn is_global(&self) -> bool {
 283         match self {
 284             IpAddr::V4(ip) => ip.is_global(),
 285             IpAddr::V6(ip) => ip.is_global(),
 286         }
 287     }
 288
 289     /// Returns [`true`] if this is a multicast address.
 290     ///
 291     /// See the documentation for [`Ipv4Addr::is_multicast()`] and
 292     /// [`Ipv6Addr::is_multicast()`] for more details.
 293     ///
 294     /// # Examples
 295     ///
 296     /// ```
 297     /// use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
 298     ///
 299     /// assert_eq!(IpAddr::V4(Ipv4Addr::new(224, 254, 0, 0)).is_multicast(), true);
 300     /// assert_eq!(IpAddr::V6(Ipv6Addr::new(0xff00, 0, 0, 0, 0, 0, 0, 0)).is_multicast(), true);
 301     /// ```
 302     #[rustc_const_stable(feature = "const_ip_50", since = "1.50.0")]
 303     #[stable(feature = "ip_shared", since = "1.12.0")]
 304     #[must_use]
 305     #[inline]
 306     pub const fn is_multicast(&self) -> bool {
 307         match self {
 308             IpAddr::V4(ip) => ip.is_multicast(),
 309             IpAddr::V6(ip) => ip.is_multicast(),
 310         }
 311     }
 312
 313     /// Returns [`true`] if this address is in a range designated for documentation.
 314     ///
 315     /// See the documentation for [`Ipv4Addr::is_documentation()`] and
 316     /// [`Ipv6Addr::is_documentation()`] for more details.
 317     ///
 318     /// # Examples
 319     ///
 320     /// ```
 321     /// #![feature(ip)]
 322     ///
 323     /// use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
 324     ///
 325     /// assert_eq!(IpAddr::V4(Ipv4Addr::new(203, 0, 113, 6)).is_documentation(), true);
 326     /// assert_eq!(
 327     ///     IpAddr::V6(Ipv6Addr::new(0x2001, 0xdb8, 0, 0, 0, 0, 0, 0)).is_documentation(),
 328     ///     true
 329     /// );
 330     /// ```
 331     #[rustc_const_unstable(feature = "const_ip", issue = "76205")]
 332     #[unstable(feature = "ip", issue = "27709")]
 333     #[must_use]
 334     #[inline]
 335     pub const fn is_documentation(&self) -> bool {
 336         match self {
 337             IpAddr::V4(ip) => ip.is_documentation(),
 338             IpAddr::V6(ip) => ip.is_documentation(),
 339         }
 340     }
 341
 342     /// Returns [`true`] if this address is in a range designated for benchmarking.
 343     ///
 344     /// See the documentation for [`Ipv4Addr::is_benchmarking()`] and
 345     /// [`Ipv6Addr::is_benchmarking()`] for more details.
 346     ///
 347     /// # Examples
 348     ///
 349     /// ```
 350     /// #![feature(ip)]
 351     ///
 352     /// use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
 353     ///
 354     /// assert_eq!(IpAddr::V4(Ipv4Addr::new(198, 19, 255, 255)).is_benchmarking(), true);
 355     /// assert_eq!(IpAddr::V6(Ipv6Addr::new(0x2001, 0x2, 0, 0, 0, 0, 0, 0)).is_benchmarking(), true);
 356     /// ```
 357     #[unstable(feature = "ip", issue = "27709")]
 358     #[must_use]
 359     #[inline]
 360     pub const fn is_benchmarking(&self) -> bool {
 361         match self {
 362             IpAddr::V4(ip) => ip.is_benchmarking(),
 363             IpAddr::V6(ip) => ip.is_benchmarking(),
 364         }
 365     }
 366
 367     /// Returns [`true`] if this address is an [`IPv4` address], and [`false`]
 368     /// otherwise.
 369     ///
 370     /// [`IPv4` address]: IpAddr::V4
 371     ///
 372     /// # Examples
 373     ///
 374     /// ```
 375     /// use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
 376     ///
 377     /// assert_eq!(IpAddr::V4(Ipv4Addr::new(203, 0, 113, 6)).is_ipv4(), true);
 378     /// assert_eq!(IpAddr::V6(Ipv6Addr::new(0x2001, 0xdb8, 0, 0, 0, 0, 0, 0)).is_ipv4(), false);
 379     /// ```
 380     #[rustc_const_stable(feature = "const_ip_50", since = "1.50.0")]
 381     #[stable(feature = "ipaddr_checker", since = "1.16.0")]
 382     #[must_use]
 383     #[inline]
 384     pub const fn is_ipv4(&self) -> bool {
 385         matches!(self, IpAddr::V4(_))
 386     }
 387
 388     /// Returns [`true`] if this address is an [`IPv6` address], and [`false`]
 389     /// otherwise.
 390     ///
 391     /// [`IPv6` address]: IpAddr::V6
 392     ///
 393     /// # Examples
 394     ///
 395     /// ```
 396     /// use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
 397     ///
 398     /// assert_eq!(IpAddr::V4(Ipv4Addr::new(203, 0, 113, 6)).is_ipv6(), false);
 399     /// assert_eq!(IpAddr::V6(Ipv6Addr::new(0x2001, 0xdb8, 0, 0, 0, 0, 0, 0)).is_ipv6(), true);
 400     /// ```
 401     #[rustc_const_stable(feature = "const_ip_50", since = "1.50.0")]
 402     #[stable(feature = "ipaddr_checker", since = "1.16.0")]
 403     #[must_use]
 404     #[inline]
 405     pub const fn is_ipv6(&self) -> bool {
 406         matches!(self, IpAddr::V6(_))
 407     }
 408
 409     /// Converts this address to an `IpAddr::V4` if it is an IPv4-mapped IPv6 addresses, otherwise it
 410     /// return `self` as-is.
 411     ///
 412     /// # Examples
 413     ///
 414     /// ```
 415     /// use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
 416     ///
 417     /// let localhost_v4 = Ipv4Addr::new(127, 0, 0, 1);
 418     ///
 419     /// assert_eq!(IpAddr::V4(localhost_v4).to_canonical(), localhost_v4);
 420     /// assert_eq!(IpAddr::V6(localhost_v4.to_ipv6_mapped()).to_canonical(), localhost_v4);
 421     /// assert_eq!(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)).to_canonical().is_loopback(), true);
 422     /// assert_eq!(IpAddr::V6(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0x7f00, 0x1)).is_loopback(), false);
 423     /// assert_eq!(IpAddr::V6(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0x7f00, 0x1)).to_canonical().is_loopback(), true);
 424     /// ```
 425     #[inline]
 426     #[must_use = "this returns the result of the operation, \
 427                   without modifying the original"]
 428     #[stable(feature = "ip_to_canonical", since = "1.75.0")]
 429     #[rustc_const_stable(feature = "ip_to_canonical", since = "1.75.0")]
 430     pub const fn to_canonical(&self) -> IpAddr {
 431         match self {
 432             IpAddr::V4(_) => *self,
 433             IpAddr::V6(v6) => v6.to_canonical(),
 434         }
 435     }
 436 }
 437
 438 impl Ipv4Addr {
 439     /// Creates a new IPv4 address from four eight-bit octets.
 440     ///
 441     /// The result will represent the IP address `a`.`b`.`c`.`d`.
 442     ///
 443     /// # Examples
 444     ///
 445     /// ```
 446     /// use std::net::Ipv4Addr;
 447     ///
 448     /// let addr = Ipv4Addr::new(127, 0, 0, 1);
 449     /// ```
 450     #[rustc_const_stable(feature = "const_ip_32", since = "1.32.0")]
 451     #[stable(feature = "rust1", since = "1.0.0")]
 452     #[must_use]
 453     #[inline]
 454     pub const fn new(a: u8, b: u8, c: u8, d: u8) -> Ipv4Addr {
 455         Ipv4Addr { octets: [a, b, c, d] }
 456     }
 457
 458     /// The size of an IPv4 address in bits.
 459     ///
 460     /// # Examples
 461     ///
 462     /// ```
 463     /// #![feature(ip_bits)]
 464     /// use std::net::Ipv4Addr;
 465     ///
 466     /// assert_eq!(Ipv4Addr::BITS, 32);
 467     /// ```
 468     #[unstable(feature = "ip_bits", issue = "113744")]
 469     pub const BITS: u32 = 32;
 470
 471     /// Converts an IPv4 address into host byte order `u32`.
 472     ///
 473     /// # Examples
 474     ///
 475     /// ```
 476     /// #![feature(ip_bits)]
 477     /// use std::net::Ipv4Addr;
 478     ///
 479     /// let addr = Ipv4Addr::new(0x12, 0x34, 0x56, 0x78);
 480     /// assert_eq!(0x12345678, addr.to_bits());
 481     /// ```
 482     #[rustc_const_unstable(feature = "ip_bits", issue = "113744")]
 483     #[unstable(feature = "ip_bits", issue = "113744")]
 484     #[must_use]
 485     #[inline]
 486     pub const fn to_bits(self) -> u32 {
 487         u32::from_be_bytes(self.octets)
 488     }
 489
 490     /// Converts a host byte order `u32` into an IPv4 address.
 491     ///
 492     /// # Examples
 493     ///
 494     /// ```
 495     /// #![feature(ip_bits)]
 496     /// use std::net::Ipv4Addr;
 497     ///
 498     /// let addr = Ipv4Addr::from(0x12345678);
 499     /// assert_eq!(Ipv4Addr::new(0x12, 0x34, 0x56, 0x78), addr);
 500     /// ```
 501     #[rustc_const_unstable(feature = "ip_bits", issue = "113744")]
 502     #[unstable(feature = "ip_bits", issue = "113744")]
 503     #[must_use]
 504     #[inline]
 505     pub const fn from_bits(bits: u32) -> Ipv4Addr {
 506         Ipv4Addr { octets: bits.to_be_bytes() }
 507     }
 508
 509     /// An IPv4 address with the address pointing to localhost: `127.0.0.1`
 510     ///
 511     /// # Examples
 512     ///
 513     /// ```
 514     /// use std::net::Ipv4Addr;
 515     ///
 516     /// let addr = Ipv4Addr::LOCALHOST;
 517     /// assert_eq!(addr, Ipv4Addr::new(127, 0, 0, 1));
 518     /// ```
 519     #[stable(feature = "ip_constructors", since = "1.30.0")]
 520     pub const LOCALHOST: Self = Ipv4Addr::new(127, 0, 0, 1);
 521
 522     /// An IPv4 address representing an unspecified address: `0.0.0.0`
 523     ///
 524     /// This corresponds to the constant `INADDR_ANY` in other languages.
 525     ///
 526     /// # Examples
 527     ///
 528     /// ```
 529     /// use std::net::Ipv4Addr;
 530     ///
 531     /// let addr = Ipv4Addr::UNSPECIFIED;
 532     /// assert_eq!(addr, Ipv4Addr::new(0, 0, 0, 0));
 533     /// ```
 534     #[doc(alias = "INADDR_ANY")]
 535     #[stable(feature = "ip_constructors", since = "1.30.0")]
 536     pub const UNSPECIFIED: Self = Ipv4Addr::new(0, 0, 0, 0);
 537
 538     /// An IPv4 address representing the broadcast address: `255.255.255.255`
 539     ///
 540     /// # Examples
 541     ///
 542     /// ```
 543     /// use std::net::Ipv4Addr;
 544     ///
 545     /// let addr = Ipv4Addr::BROADCAST;
 546     /// assert_eq!(addr, Ipv4Addr::new(255, 255, 255, 255));
 547     /// ```
 548     #[stable(feature = "ip_constructors", since = "1.30.0")]
 549     pub const BROADCAST: Self = Ipv4Addr::new(255, 255, 255, 255);
 550
 551     /// Returns the four eight-bit integers that make up this address.
 552     ///
 553     /// # Examples
 554     ///
 555     /// ```
 556     /// use std::net::Ipv4Addr;
 557     ///
 558     /// let addr = Ipv4Addr::new(127, 0, 0, 1);
 559     /// assert_eq!(addr.octets(), [127, 0, 0, 1]);
 560     /// ```
 561     #[rustc_const_stable(feature = "const_ip_50", since = "1.50.0")]
 562     #[stable(feature = "rust1", since = "1.0.0")]
 563     #[must_use]
 564     #[inline]
 565     pub const fn octets(&self) -> [u8; 4] {
 566         self.octets
 567     }
 568
 569     /// Returns [`true`] for the special 'unspecified' address (`0.0.0.0`).
 570     ///
 571     /// This property is defined in _UNIX Network Programming, Second Edition_,
 572     /// W. Richard Stevens, p. 891; see also [ip7].
 573     ///
 574     /// [ip7]: https://man7.org/linux/man-pages/man7/ip.7.html
 575     ///
 576     /// # Examples
 577     ///
 578     /// ```
 579     /// use std::net::Ipv4Addr;
 580     ///
 581     /// assert_eq!(Ipv4Addr::new(0, 0, 0, 0).is_unspecified(), true);
 582     /// assert_eq!(Ipv4Addr::new(45, 22, 13, 197).is_unspecified(), false);
 583     /// ```
 584     #[rustc_const_stable(feature = "const_ip_32", since = "1.32.0")]
 585     #[stable(feature = "ip_shared", since = "1.12.0")]
 586     #[must_use]
 587     #[inline]
 588     pub const fn is_unspecified(&self) -> bool {
 589         u32::from_be_bytes(self.octets) == 0
 590     }
 591
 592     /// Returns [`true`] if this is a loopback address (`127.0.0.0/8`).
 593     ///
 594     /// This property is defined by [IETF RFC 1122].
 595     ///
 596     /// [IETF RFC 1122]: https://tools.ietf.org/html/rfc1122
 597     ///
 598     /// # Examples
 599     ///
 600     /// ```
 601     /// use std::net::Ipv4Addr;
 602     ///
 603     /// assert_eq!(Ipv4Addr::new(127, 0, 0, 1).is_loopback(), true);
 604     /// assert_eq!(Ipv4Addr::new(45, 22, 13, 197).is_loopback(), false);
 605     /// ```
 606     #[rustc_const_stable(feature = "const_ip_50", since = "1.50.0")]
 607     #[stable(since = "1.7.0", feature = "ip_17")]
 608     #[must_use]
 609     #[inline]
 610     pub const fn is_loopback(&self) -> bool {
 611         self.octets()[0] == 127
 612     }
 613
 614     /// Returns [`true`] if this is a private address.
 615     ///
 616     /// The private address ranges are defined in [IETF RFC 1918] and include:
 617     ///
 618     ///  - `10.0.0.0/8`
 619     ///  - `172.16.0.0/12`
 620     ///  - `192.168.0.0/16`
 621     ///
 622     /// [IETF RFC 1918]: https://tools.ietf.org/html/rfc1918
 623     ///
 624     /// # Examples
 625     ///
 626     /// ```
 627     /// use std::net::Ipv4Addr;
 628     ///
 629     /// assert_eq!(Ipv4Addr::new(10, 0, 0, 1).is_private(), true);
 630     /// assert_eq!(Ipv4Addr::new(10, 10, 10, 10).is_private(), true);
 631     /// assert_eq!(Ipv4Addr::new(172, 16, 10, 10).is_private(), true);
 632     /// assert_eq!(Ipv4Addr::new(172, 29, 45, 14).is_private(), true);
 633     /// assert_eq!(Ipv4Addr::new(172, 32, 0, 2).is_private(), false);
 634     /// assert_eq!(Ipv4Addr::new(192, 168, 0, 2).is_private(), true);
 635     /// assert_eq!(Ipv4Addr::new(192, 169, 0, 2).is_private(), false);
 636     /// ```
 637     #[rustc_const_stable(feature = "const_ip_50", since = "1.50.0")]
 638     #[stable(since = "1.7.0", feature = "ip_17")]
 639     #[must_use]
 640     #[inline]
 641     pub const fn is_private(&self) -> bool {
 642         match self.octets() {
 643             [10, ..] => true,
 644             [172, b, ..] if b >= 16 && b <= 31 => true,
 645             [192, 168, ..] => true,
 646             _ => false,
 647         }
 648     }
 649
 650     /// Returns [`true`] if the address is link-local (`169.254.0.0/16`).
 651     ///
 652     /// This property is defined by [IETF RFC 3927].
 653     ///
 654     /// [IETF RFC 3927]: https://tools.ietf.org/html/rfc3927
 655     ///
 656     /// # Examples
 657     ///
 658     /// ```
 659     /// use std::net::Ipv4Addr;
 660     ///
 661     /// assert_eq!(Ipv4Addr::new(169, 254, 0, 0).is_link_local(), true);
 662     /// assert_eq!(Ipv4Addr::new(169, 254, 10, 65).is_link_local(), true);
 663     /// assert_eq!(Ipv4Addr::new(16, 89, 10, 65).is_link_local(), false);
 664     /// ```
 665     #[rustc_const_stable(feature = "const_ip_50", since = "1.50.0")]
 666     #[stable(since = "1.7.0", feature = "ip_17")]
 667     #[must_use]
 668     #[inline]
 669     pub const fn is_link_local(&self) -> bool {
 670         matches!(self.octets(), [169, 254, ..])
 671     }
 672
 673     /// Returns [`true`] if the address appears to be globally reachable
 674     /// as specified by the [IANA IPv4 Special-Purpose Address Registry].
 675     /// Whether or not an address is practically reachable will depend on your network configuration.
 676     ///
 677     /// Most IPv4 addresses are globally reachable;
 678     /// unless they are specifically defined as *not* globally reachable.
 679     ///
 680     /// Non-exhaustive list of notable addresses that are not globally reachable:
 681     ///
 682     /// - The [unspecified address] ([`is_unspecified`](Ipv4Addr::is_unspecified))
 683     /// - Addresses reserved for private use ([`is_private`](Ipv4Addr::is_private))
 684     /// - Addresses in the shared address space ([`is_shared`](Ipv4Addr::is_shared))
 685     /// - Loopback addresses ([`is_loopback`](Ipv4Addr::is_loopback))
 686     /// - Link-local addresses ([`is_link_local`](Ipv4Addr::is_link_local))
 687     /// - Addresses reserved for documentation ([`is_documentation`](Ipv4Addr::is_documentation))
 688     /// - Addresses reserved for benchmarking ([`is_benchmarking`](Ipv4Addr::is_benchmarking))
 689     /// - Reserved addresses ([`is_reserved`](Ipv4Addr::is_reserved))
 690     /// - The [broadcast address] ([`is_broadcast`](Ipv4Addr::is_broadcast))
 691     ///
 692     /// For the complete overview of which addresses are globally reachable, see the table at the [IANA IPv4 Special-Purpose Address Registry].
 693     ///
 694     /// [IANA IPv4 Special-Purpose Address Registry]: https://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml
 695     /// [unspecified address]: Ipv4Addr::UNSPECIFIED
 696     /// [broadcast address]: Ipv4Addr::BROADCAST
 697
 698     ///
 699     /// # Examples
 700     ///
 701     /// ```
 702     /// #![feature(ip)]
 703     ///
 704     /// use std::net::Ipv4Addr;
 705     ///
 706     /// // Most IPv4 addresses are globally reachable:
 707     /// assert_eq!(Ipv4Addr::new(80, 9, 12, 3).is_global(), true);
 708     ///
 709     /// // However some addresses have been assigned a special meaning
 710     /// // that makes them not globally reachable. Some examples are:
 711     ///
 712     /// // The unspecified address (`0.0.0.0`)
 713     /// assert_eq!(Ipv4Addr::UNSPECIFIED.is_global(), false);
 714     ///
 715     /// // Addresses reserved for private use (`10.0.0.0/8`, `172.16.0.0/12`, 192.168.0.0/16)
 716     /// assert_eq!(Ipv4Addr::new(10, 254, 0, 0).is_global(), false);
 717     /// assert_eq!(Ipv4Addr::new(192, 168, 10, 65).is_global(), false);
 718     /// assert_eq!(Ipv4Addr::new(172, 16, 10, 65).is_global(), false);
 719     ///
 720     /// // Addresses in the shared address space (`100.64.0.0/10`)
 721     /// assert_eq!(Ipv4Addr::new(100, 100, 0, 0).is_global(), false);
 722     ///
 723     /// // The loopback addresses (`127.0.0.0/8`)
 724     /// assert_eq!(Ipv4Addr::LOCALHOST.is_global(), false);
 725     ///
 726     /// // Link-local addresses (`169.254.0.0/16`)
 727     /// assert_eq!(Ipv4Addr::new(169, 254, 45, 1).is_global(), false);
 728     ///
 729     /// // Addresses reserved for documentation (`192.0.2.0/24`, `198.51.100.0/24`, `203.0.113.0/24`)
 730     /// assert_eq!(Ipv4Addr::new(192, 0, 2, 255).is_global(), false);
 731     /// assert_eq!(Ipv4Addr::new(198, 51, 100, 65).is_global(), false);
 732     /// assert_eq!(Ipv4Addr::new(203, 0, 113, 6).is_global(), false);
 733     ///
 734     /// // Addresses reserved for benchmarking (`198.18.0.0/15`)
 735     /// assert_eq!(Ipv4Addr::new(198, 18, 0, 0).is_global(), false);
 736     ///
 737     /// // Reserved addresses (`240.0.0.0/4`)
 738     /// assert_eq!(Ipv4Addr::new(250, 10, 20, 30).is_global(), false);
 739     ///
 740     /// // The broadcast address (`255.255.255.255`)
 741     /// assert_eq!(Ipv4Addr::BROADCAST.is_global(), false);
 742     ///
 743     /// // For a complete overview see the IANA IPv4 Special-Purpose Address Registry.
 744     /// ```
 745     #[rustc_const_unstable(feature = "const_ipv4", issue = "76205")]
 746     #[unstable(feature = "ip", issue = "27709")]
 747     #[must_use]
 748     #[inline]
 749     pub const fn is_global(&self) -> bool {
 750         !(self.octets()[0] == 0 // "This network"
 751             || self.is_private()
 752             || self.is_shared()
 753             || self.is_loopback()
 754             || self.is_link_local()
 755             // addresses reserved for future protocols (`192.0.0.0/24`)
 756             ||(self.octets()[0] == 192 && self.octets()[1] == 0 && self.octets()[2] == 0)
 757             || self.is_documentation()
 758             || self.is_benchmarking()
 759             || self.is_reserved()
 760             || self.is_broadcast())
 761     }
 762
 763     /// Returns [`true`] if this address is part of the Shared Address Space defined in
 764     /// [IETF RFC 6598] (`100.64.0.0/10`).
 765     ///
 766     /// [IETF RFC 6598]: https://tools.ietf.org/html/rfc6598
 767     ///
 768     /// # Examples
 769     ///
 770     /// ```
 771     /// #![feature(ip)]
 772     /// use std::net::Ipv4Addr;
 773     ///
 774     /// assert_eq!(Ipv4Addr::new(100, 64, 0, 0).is_shared(), true);
 775     /// assert_eq!(Ipv4Addr::new(100, 127, 255, 255).is_shared(), true);
 776     /// assert_eq!(Ipv4Addr::new(100, 128, 0, 0).is_shared(), false);
 777     /// ```
 778     #[rustc_const_unstable(feature = "const_ipv4", issue = "76205")]
 779     #[unstable(feature = "ip", issue = "27709")]
 780     #[must_use]
 781     #[inline]
 782     pub const fn is_shared(&self) -> bool {
 783         self.octets()[0] == 100 && (self.octets()[1] & 0b1100_0000 == 0b0100_0000)
 784     }
 785
 786     /// Returns [`true`] if this address part of the `198.18.0.0/15` range, which is reserved for
 787     /// network devices benchmarking. This range is defined in [IETF RFC 2544] as `192.18.0.0`
 788     /// through `198.19.255.255` but [errata 423] corrects it to `198.18.0.0/15`.
 789     ///
 790     /// [IETF RFC 2544]: https://tools.ietf.org/html/rfc2544
 791     /// [errata 423]: https://www.rfc-editor.org/errata/eid423
 792     ///
 793     /// # Examples
 794     ///
 795     /// ```
 796     /// #![feature(ip)]
 797     /// use std::net::Ipv4Addr;
 798     ///
 799     /// assert_eq!(Ipv4Addr::new(198, 17, 255, 255).is_benchmarking(), false);
 800     /// assert_eq!(Ipv4Addr::new(198, 18, 0, 0).is_benchmarking(), true);
 801     /// assert_eq!(Ipv4Addr::new(198, 19, 255, 255).is_benchmarking(), true);
 802     /// assert_eq!(Ipv4Addr::new(198, 20, 0, 0).is_benchmarking(), false);
 803     /// ```
 804     #[rustc_const_unstable(feature = "const_ipv4", issue = "76205")]
 805     #[unstable(feature = "ip", issue = "27709")]
 806     #[must_use]
 807     #[inline]
 808     pub const fn is_benchmarking(&self) -> bool {
 809         self.octets()[0] == 198 && (self.octets()[1] & 0xfe) == 18
 810     }
 811
 812     /// Returns [`true`] if this address is reserved by IANA for future use. [IETF RFC 1112]
 813     /// defines the block of reserved addresses as `240.0.0.0/4`. This range normally includes the
 814     /// broadcast address `255.255.255.255`, but this implementation explicitly excludes it, since
 815     /// it is obviously not reserved for future use.
 816     ///
 817     /// [IETF RFC 1112]: https://tools.ietf.org/html/rfc1112
 818     ///
 819     /// # Warning
 820     ///
 821     /// As IANA assigns new addresses, this method will be
 822     /// updated. This may result in non-reserved addresses being
 823     /// treated as reserved in code that relies on an outdated version
 824     /// of this method.
 825     ///
 826     /// # Examples
 827     ///
 828     /// ```
 829     /// #![feature(ip)]
 830     /// use std::net::Ipv4Addr;
 831     ///
 832     /// assert_eq!(Ipv4Addr::new(240, 0, 0, 0).is_reserved(), true);
 833     /// assert_eq!(Ipv4Addr::new(255, 255, 255, 254).is_reserved(), true);
 834     ///
 835     /// assert_eq!(Ipv4Addr::new(239, 255, 255, 255).is_reserved(), false);
 836     /// // The broadcast address is not considered as reserved for future use by this implementation
 837     /// assert_eq!(Ipv4Addr::new(255, 255, 255, 255).is_reserved(), false);
 838     /// ```
 839     #[rustc_const_unstable(feature = "const_ipv4", issue = "76205")]
 840     #[unstable(feature = "ip", issue = "27709")]
 841     #[must_use]
 842     #[inline]
 843     pub const fn is_reserved(&self) -> bool {
 844         self.octets()[0] & 240 == 240 && !self.is_broadcast()
 845     }
 846
 847     /// Returns [`true`] if this is a multicast address (`224.0.0.0/4`).
 848     ///
 849     /// Multicast addresses have a most significant octet between `224` and `239`,
 850     /// and is defined by [IETF RFC 5771].
 851     ///
 852     /// [IETF RFC 5771]: https://tools.ietf.org/html/rfc5771
 853     ///
 854     /// # Examples
 855     ///
 856     /// ```
 857     /// use std::net::Ipv4Addr;
 858     ///
 859     /// assert_eq!(Ipv4Addr::new(224, 254, 0, 0).is_multicast(), true);
 860     /// assert_eq!(Ipv4Addr::new(236, 168, 10, 65).is_multicast(), true);
 861     /// assert_eq!(Ipv4Addr::new(172, 16, 10, 65).is_multicast(), false);
 862     /// ```
 863     #[rustc_const_stable(feature = "const_ip_50", since = "1.50.0")]
 864     #[stable(since = "1.7.0", feature = "ip_17")]
 865     #[must_use]
 866     #[inline]
 867     pub const fn is_multicast(&self) -> bool {
 868         self.octets()[0] >= 224 && self.octets()[0] <= 239
 869     }
 870
 871     /// Returns [`true`] if this is a broadcast address (`255.255.255.255`).
 872     ///
 873     /// A broadcast address has all octets set to `255` as defined in [IETF RFC 919].
 874     ///
 875     /// [IETF RFC 919]: https://tools.ietf.org/html/rfc919
 876     ///
 877     /// # Examples
 878     ///
 879     /// ```
 880     /// use std::net::Ipv4Addr;
 881     ///
 882     /// assert_eq!(Ipv4Addr::new(255, 255, 255, 255).is_broadcast(), true);
 883     /// assert_eq!(Ipv4Addr::new(236, 168, 10, 65).is_broadcast(), false);
 884     /// ```
 885     #[rustc_const_stable(feature = "const_ip_50", since = "1.50.0")]
 886     #[stable(since = "1.7.0", feature = "ip_17")]
 887     #[must_use]
 888     #[inline]
 889     pub const fn is_broadcast(&self) -> bool {
 890         u32::from_be_bytes(self.octets()) == u32::from_be_bytes(Self::BROADCAST.octets())
 891     }
 892
 893     /// Returns [`true`] if this address is in a range designated for documentation.
 894     ///
 895     /// This is defined in [IETF RFC 5737]:
 896     ///
 897     /// - `192.0.2.0/24` (TEST-NET-1)
 898     /// - `198.51.100.0/24` (TEST-NET-2)
 899     /// - `203.0.113.0/24` (TEST-NET-3)
 900     ///
 901     /// [IETF RFC 5737]: https://tools.ietf.org/html/rfc5737
 902     ///
 903     /// # Examples
 904     ///
 905     /// ```
 906     /// use std::net::Ipv4Addr;
 907     ///
 908     /// assert_eq!(Ipv4Addr::new(192, 0, 2, 255).is_documentation(), true);
 909     /// assert_eq!(Ipv4Addr::new(198, 51, 100, 65).is_documentation(), true);
 910     /// assert_eq!(Ipv4Addr::new(203, 0, 113, 6).is_documentation(), true);
 911     /// assert_eq!(Ipv4Addr::new(193, 34, 17, 19).is_documentation(), false);
 912     /// ```
 913     #[rustc_const_stable(feature = "const_ip_50", since = "1.50.0")]
 914     #[stable(since = "1.7.0", feature = "ip_17")]
 915     #[must_use]
 916     #[inline]
 917     pub const fn is_documentation(&self) -> bool {
 918         matches!(self.octets(), [192, 0, 2, _] | [198, 51, 100, _] | [203, 0, 113, _])
 919     }
 920
 921     /// Converts this address to an [IPv4-compatible] [`IPv6` address].
 922     ///
 923     /// `a.b.c.d` becomes `::a.b.c.d`
 924     ///
 925     /// Note that IPv4-compatible addresses have been officially deprecated.
 926     /// If you don't explicitly need an IPv4-compatible address for legacy reasons, consider using `to_ipv6_mapped` instead.
 927     ///
 928     /// [IPv4-compatible]: Ipv6Addr#ipv4-compatible-ipv6-addresses
 929     /// [`IPv6` address]: Ipv6Addr
 930     ///
 931     /// # Examples
 932     ///
 933     /// ```
 934     /// use std::net::{Ipv4Addr, Ipv6Addr};
 935     ///
 936     /// assert_eq!(
 937     ///     Ipv4Addr::new(192, 0, 2, 255).to_ipv6_compatible(),
 938     ///     Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0xc000, 0x2ff)
 939     /// );
 940     /// ```
 941     #[rustc_const_stable(feature = "const_ip_50", since = "1.50.0")]
 942     #[stable(feature = "rust1", since = "1.0.0")]
 943     #[must_use = "this returns the result of the operation, \
 944                   without modifying the original"]
 945     #[inline]
 946     pub const fn to_ipv6_compatible(&self) -> Ipv6Addr {
 947         let [a, b, c, d] = self.octets();
 948         Ipv6Addr { octets: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, a, b, c, d] }
 949     }
 950
 951     /// Converts this address to an [IPv4-mapped] [`IPv6` address].
 952     ///
 953     /// `a.b.c.d` becomes `::ffff:a.b.c.d`
 954     ///
 955     /// [IPv4-mapped]: Ipv6Addr#ipv4-mapped-ipv6-addresses
 956     /// [`IPv6` address]: Ipv6Addr
 957     ///
 958     /// # Examples
 959     ///
 960     /// ```
 961     /// use std::net::{Ipv4Addr, Ipv6Addr};
 962     ///
 963     /// assert_eq!(Ipv4Addr::new(192, 0, 2, 255).to_ipv6_mapped(),
 964     ///            Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0xc000, 0x2ff));
 965     /// ```
 966     #[rustc_const_stable(feature = "const_ip_50", since = "1.50.0")]
 967     #[stable(feature = "rust1", since = "1.0.0")]
 968     #[must_use = "this returns the result of the operation, \
 969                   without modifying the original"]
 970     #[inline]
 971     pub const fn to_ipv6_mapped(&self) -> Ipv6Addr {
 972         let [a, b, c, d] = self.octets();
 973         Ipv6Addr { octets: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, a, b, c, d] }
 974     }
 975 }
 976
 977 #[stable(feature = "ip_addr", since = "1.7.0")]
 978 impl fmt::Display for IpAddr {
 979     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
 980         match self {
 981             IpAddr::V4(ip) => ip.fmt(fmt),
 982             IpAddr::V6(ip) => ip.fmt(fmt),
 983         }
 984     }
 985 }
 986
 987 #[stable(feature = "ip_addr", since = "1.7.0")]
 988 impl fmt::Debug for IpAddr {
 989     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
 990         fmt::Display::fmt(self, fmt)
 991     }
 992 }
 993
 994 #[stable(feature = "ip_from_ip", since = "1.16.0")]
 995 impl From<Ipv4Addr> for IpAddr {
 996     /// Copies this address to a new `IpAddr::V4`.
 997     ///
 998     /// # Examples
 999     ///
1000     /// ```
1001     /// use std::net::{IpAddr, Ipv4Addr};
1002     ///
1003     /// let addr = Ipv4Addr::new(127, 0, 0, 1);
1004     ///
1005     /// assert_eq!(
1006     ///     IpAddr::V4(addr),
1007     ///     IpAddr::from(addr)
1008     /// )
1009     /// ```
1010     #[inline]
1011     fn from(ipv4: Ipv4Addr) -> IpAddr {
1012         IpAddr::V4(ipv4)
1013     }
1014 }
1015
1016 #[stable(feature = "ip_from_ip", since = "1.16.0")]
1017 impl From<Ipv6Addr> for IpAddr {
1018     /// Copies this address to a new `IpAddr::V6`.
1019     ///
1020     /// # Examples
1021     ///
1022     /// ```
1023     /// use std::net::{IpAddr, Ipv6Addr};
1024     ///
1025     /// let addr = Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0xc00a, 0x2ff);
1026     ///
1027     /// assert_eq!(
1028     ///     IpAddr::V6(addr),
1029     ///     IpAddr::from(addr)
1030     /// );
1031     /// ```
1032     #[inline]
1033     fn from(ipv6: Ipv6Addr) -> IpAddr {
1034         IpAddr::V6(ipv6)
1035     }
1036 }
1037
1038 #[stable(feature = "rust1", since = "1.0.0")]
1039 impl fmt::Display for Ipv4Addr {
1040     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
1041         let octets = self.octets();
1042
1043         // If there are no alignment requirements, write the IP address directly to `f`.
1044         // Otherwise, write it to a local buffer and then use `f.pad`.
1045         if fmt.precision().is_none() && fmt.width().is_none() {
1046             write!(fmt, "{}.{}.{}.{}", octets[0], octets[1], octets[2], octets[3])
1047         } else {
1048             const LONGEST_IPV4_ADDR: &str = "255.255.255.255";
1049
1050             let mut buf = DisplayBuffer::<{ LONGEST_IPV4_ADDR.len() }>::new();
1051             // Buffer is long enough for the longest possible IPv4 address, so this should never fail.
1052             write!(buf, "{}.{}.{}.{}", octets[0], octets[1], octets[2], octets[3]).unwrap();
1053
1054             fmt.pad(buf.as_str())
1055         }
1056     }
1057 }
1058
1059 #[stable(feature = "rust1", since = "1.0.0")]
1060 impl fmt::Debug for Ipv4Addr {
1061     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
1062         fmt::Display::fmt(self, fmt)
1063     }
1064 }
1065
1066 #[stable(feature = "ip_cmp", since = "1.16.0")]
1067 impl PartialEq<Ipv4Addr> for IpAddr {
1068     #[inline]
1069     fn eq(&self, other: &Ipv4Addr) -> bool {
1070         match self {
1071             IpAddr::V4(v4) => v4 == other,
1072             IpAddr::V6(_) => false,
1073         }
1074     }
1075 }
1076
1077 #[stable(feature = "ip_cmp", since = "1.16.0")]
1078 impl PartialEq<IpAddr> for Ipv4Addr {
1079     #[inline]
1080     fn eq(&self, other: &IpAddr) -> bool {
1081         match other {
1082             IpAddr::V4(v4) => self == v4,
1083             IpAddr::V6(_) => false,
1084         }
1085     }
1086 }
1087
1088 #[stable(feature = "rust1", since = "1.0.0")]
1089 impl PartialOrd for Ipv4Addr {
1090     #[inline]
1091     fn partial_cmp(&self, other: &Ipv4Addr) -> Option<Ordering> {
1092         Some(self.cmp(other))
1093     }
1094 }
1095
1096 #[stable(feature = "ip_cmp", since = "1.16.0")]
1097 impl PartialOrd<Ipv4Addr> for IpAddr {
1098     #[inline]
1099     fn partial_cmp(&self, other: &Ipv4Addr) -> Option<Ordering> {
1100         match self {
1101             IpAddr::V4(v4) => v4.partial_cmp(other),
1102             IpAddr::V6(_) => Some(Ordering::Greater),
1103         }
1104     }
1105 }
1106
1107 #[stable(feature = "ip_cmp", since = "1.16.0")]
1108 impl PartialOrd<IpAddr> for Ipv4Addr {
1109     #[inline]
1110     fn partial_cmp(&self, other: &IpAddr) -> Option<Ordering> {
1111         match other {
1112             IpAddr::V4(v4) => self.partial_cmp(v4),
1113             IpAddr::V6(_) => Some(Ordering::Less),
1114         }
1115     }
1116 }
1117
1118 #[stable(feature = "rust1", since = "1.0.0")]
1119 impl Ord for Ipv4Addr {
1120     #[inline]
1121     fn cmp(&self, other: &Ipv4Addr) -> Ordering {
1122         self.octets.cmp(&other.octets)
1123     }
1124 }
1125
1126 #[stable(feature = "ip_u32", since = "1.1.0")]
1127 impl From<Ipv4Addr> for u32 {
1128     /// Uses [`Ipv4Addr::to_bits`] to convert an IPv4 address to a host byte order `u32`.
1129     #[inline]
1130     fn from(ip: Ipv4Addr) -> u32 {
1131         ip.to_bits()
1132     }
1133 }
1134
1135 #[stable(feature = "ip_u32", since = "1.1.0")]
1136 impl From<u32> for Ipv4Addr {
1137     /// Uses [`Ipv4Addr::from_bits`] to convert a host byte order `u32` into an IPv4 address.
1138     #[inline]
1139     fn from(ip: u32) -> Ipv4Addr {
1140         Ipv4Addr::from_bits(ip)
1141     }
1142 }
1143
1144 #[stable(feature = "from_slice_v4", since = "1.9.0")]
1145 impl From<[u8; 4]> for Ipv4Addr {
1146     /// Creates an `Ipv4Addr` from a four element byte array.
1147     ///
1148     /// # Examples
1149     ///
1150     /// ```
1151     /// use std::net::Ipv4Addr;
1152     ///
1153     /// let addr = Ipv4Addr::from([13u8, 12u8, 11u8, 10u8]);
1154     /// assert_eq!(Ipv4Addr::new(13, 12, 11, 10), addr);
1155     /// ```
1156     #[inline]
1157     fn from(octets: [u8; 4]) -> Ipv4Addr {
1158         Ipv4Addr { octets }
1159     }
1160 }
1161
1162 #[stable(feature = "ip_from_slice", since = "1.17.0")]
1163 impl From<[u8; 4]> for IpAddr {
1164     /// Creates an `IpAddr::V4` from a four element byte array.
1165     ///
1166     /// # Examples
1167     ///
1168     /// ```
1169     /// use std::net::{IpAddr, Ipv4Addr};
1170     ///
1171     /// let addr = IpAddr::from([13u8, 12u8, 11u8, 10u8]);
1172     /// assert_eq!(IpAddr::V4(Ipv4Addr::new(13, 12, 11, 10)), addr);
1173     /// ```
1174     #[inline]
1175     fn from(octets: [u8; 4]) -> IpAddr {
1176         IpAddr::V4(Ipv4Addr::from(octets))
1177     }
1178 }
1179
1180 impl Ipv6Addr {
1181     /// Creates a new IPv6 address from eight 16-bit segments.
1182     ///
1183     /// The result will represent the IP address `a:b:c:d:e:f:g:h`.
1184     ///
1185     /// # Examples
1186     ///
1187     /// ```
1188     /// use std::net::Ipv6Addr;
1189     ///
1190     /// let addr = Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0xc00a, 0x2ff);
1191     /// ```
1192     #[rustc_const_stable(feature = "const_ip_32", since = "1.32.0")]
1193     #[stable(feature = "rust1", since = "1.0.0")]
1194     #[must_use]
1195     #[inline]
1196     pub const fn new(a: u16, b: u16, c: u16, d: u16, e: u16, f: u16, g: u16, h: u16) -> Ipv6Addr {
1197         let addr16 = [
1198             a.to_be(),
1199             b.to_be(),
1200             c.to_be(),
1201             d.to_be(),
1202             e.to_be(),
1203             f.to_be(),
1204             g.to_be(),
1205             h.to_be(),
1206         ];
1207         Ipv6Addr {
1208             // All elements in `addr16` are big endian.
1209             // SAFETY: `[u16; 8]` is always safe to transmute to `[u8; 16]`.
1210             octets: unsafe { transmute::<_, [u8; 16]>(addr16) },
1211         }
1212     }
1213
1214     /// The size of an IPv6 address in bits.
1215     ///
1216     /// # Examples
1217     ///
1218     /// ```
1219     /// #![feature(ip_bits)]
1220     /// use std::net::Ipv6Addr;
1221     ///
1222     /// assert_eq!(Ipv6Addr::BITS, 128);
1223     /// ```
1224     #[unstable(feature = "ip_bits", issue = "113744")]
1225     pub const BITS: u32 = 128;
1226
1227     /// Converts an IPv6 address into host byte order `u128`.
1228     ///
1229     /// # Examples
1230     ///
1231     /// ```
1232     /// #![feature(ip_bits)]
1233     /// use std::net::Ipv6Addr;
1234     ///
1235     /// let addr = Ipv6Addr::new(
1236     ///     0x1020, 0x3040, 0x5060, 0x7080,
1237     ///     0x90A0, 0xB0C0, 0xD0E0, 0xF00D,
1238     /// );
1239     /// assert_eq!(0x102030405060708090A0B0C0D0E0F00D_u128, u128::from(addr));
1240     /// ```
1241     #[rustc_const_unstable(feature = "ip_bits", issue = "113744")]
1242     #[unstable(feature = "ip_bits", issue = "113744")]
1243     #[must_use]
1244     #[inline]
1245     pub const fn to_bits(self) -> u128 {
1246         u128::from_be_bytes(self.octets)
1247     }
1248
1249     /// Converts a host byte order `u128` into an IPv6 address.
1250     ///
1251     /// # Examples
1252     ///
1253     /// ```
1254     /// #![feature(ip_bits)]
1255     /// use std::net::Ipv6Addr;
1256     ///
1257     /// let addr = Ipv6Addr::from(0x102030405060708090A0B0C0D0E0F00D_u128);
1258     /// assert_eq!(
1259     ///     Ipv6Addr::new(
1260     ///         0x1020, 0x3040, 0x5060, 0x7080,
1261     ///         0x90A0, 0xB0C0, 0xD0E0, 0xF00D,
1262     ///     ),
1263     ///     addr);
1264     /// ```
1265     #[rustc_const_unstable(feature = "ip_bits", issue = "113744")]
1266     #[unstable(feature = "ip_bits", issue = "113744")]
1267     #[must_use]
1268     #[inline]
1269     pub const fn from_bits(bits: u128) -> Ipv6Addr {
1270         Ipv6Addr { octets: bits.to_be_bytes() }
1271     }
1272
1273     /// An IPv6 address representing localhost: `::1`.
1274     ///
1275     /// This corresponds to constant `IN6ADDR_LOOPBACK_INIT` or `in6addr_loopback` in other
1276     /// languages.
1277     ///
1278     /// # Examples
1279     ///
1280     /// ```
1281     /// use std::net::Ipv6Addr;
1282     ///
1283     /// let addr = Ipv6Addr::LOCALHOST;
1284     /// assert_eq!(addr, Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1));
1285     /// ```
1286     #[doc(alias = "IN6ADDR_LOOPBACK_INIT")]
1287     #[doc(alias = "in6addr_loopback")]
1288     #[stable(feature = "ip_constructors", since = "1.30.0")]
1289     pub const LOCALHOST: Self = Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1);
1290
1291     /// An IPv6 address representing the unspecified address: `::`
1292     ///
1293     /// This corresponds to constant `IN6ADDR_ANY_INIT` or `in6addr_any` in other languages.
1294     ///
1295     /// # Examples
1296     ///
1297     /// ```
1298     /// use std::net::Ipv6Addr;
1299     ///
1300     /// let addr = Ipv6Addr::UNSPECIFIED;
1301     /// assert_eq!(addr, Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 0));
1302     /// ```
1303     #[doc(alias = "IN6ADDR_ANY_INIT")]
1304     #[doc(alias = "in6addr_any")]
1305     #[stable(feature = "ip_constructors", since = "1.30.0")]
1306     pub const UNSPECIFIED: Self = Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 0);
1307
1308     /// Returns the eight 16-bit segments that make up this address.
1309     ///
1310     /// # Examples
1311     ///
1312     /// ```
1313     /// use std::net::Ipv6Addr;
1314     ///
1315     /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0xc00a, 0x2ff).segments(),
1316     ///            [0, 0, 0, 0, 0, 0xffff, 0xc00a, 0x2ff]);
1317     /// ```
1318     #[rustc_const_stable(feature = "const_ip_50", since = "1.50.0")]
1319     #[stable(feature = "rust1", since = "1.0.0")]
1320     #[must_use]
1321     #[inline]
1322     pub const fn segments(&self) -> [u16; 8] {
1323         // All elements in `self.octets` must be big endian.
1324         // SAFETY: `[u8; 16]` is always safe to transmute to `[u16; 8]`.
1325         let [a, b, c, d, e, f, g, h] = unsafe { transmute::<_, [u16; 8]>(self.octets) };
1326         // We want native endian u16
1327         [
1328             u16::from_be(a),
1329             u16::from_be(b),
1330             u16::from_be(c),
1331             u16::from_be(d),
1332             u16::from_be(e),
1333             u16::from_be(f),
1334             u16::from_be(g),
1335             u16::from_be(h),
1336         ]
1337     }
1338
1339     /// Returns [`true`] for the special 'unspecified' address (`::`).
1340     ///
1341     /// This property is defined in [IETF RFC 4291].
1342     ///
1343     /// [IETF RFC 4291]: https://tools.ietf.org/html/rfc4291
1344     ///
1345     /// # Examples
1346     ///
1347     /// ```
1348     /// use std::net::Ipv6Addr;
1349     ///
1350     /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0xc00a, 0x2ff).is_unspecified(), false);
1351     /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 0).is_unspecified(), true);
1352     /// ```
1353     #[rustc_const_stable(feature = "const_ip_50", since = "1.50.0")]
1354     #[stable(since = "1.7.0", feature = "ip_17")]
1355     #[must_use]
1356     #[inline]
1357     pub const fn is_unspecified(&self) -> bool {
1358         u128::from_be_bytes(self.octets()) == u128::from_be_bytes(Ipv6Addr::UNSPECIFIED.octets())
1359     }
1360
1361     /// Returns [`true`] if this is the [loopback address] (`::1`),
1362     /// as defined in [IETF RFC 4291 section 2.5.3].
1363     ///
1364     /// Contrary to IPv4, in IPv6 there is only one loopback address.
1365     ///
1366     /// [loopback address]: Ipv6Addr::LOCALHOST
1367     /// [IETF RFC 4291 section 2.5.3]: https://tools.ietf.org/html/rfc4291#section-2.5.3
1368     ///
1369     /// # Examples
1370     ///
1371     /// ```
1372     /// use std::net::Ipv6Addr;
1373     ///
1374     /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0xc00a, 0x2ff).is_loopback(), false);
1375     /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 0x1).is_loopback(), true);
1376     /// ```
1377     #[rustc_const_stable(feature = "const_ip_50", since = "1.50.0")]
1378     #[stable(since = "1.7.0", feature = "ip_17")]
1379     #[must_use]
1380     #[inline]
1381     pub const fn is_loopback(&self) -> bool {
1382         u128::from_be_bytes(self.octets()) == u128::from_be_bytes(Ipv6Addr::LOCALHOST.octets())
1383     }
1384
1385     /// Returns [`true`] if the address appears to be globally reachable
1386     /// as specified by the [IANA IPv6 Special-Purpose Address Registry].
1387     /// Whether or not an address is practically reachable will depend on your network configuration.
1388     ///
1389     /// Most IPv6 addresses are globally reachable;
1390     /// unless they are specifically defined as *not* globally reachable.
1391     ///
1392     /// Non-exhaustive list of notable addresses that are not globally reachable:
1393     /// - The [unspecified address] ([`is_unspecified`](Ipv6Addr::is_unspecified))
1394     /// - The [loopback address] ([`is_loopback`](Ipv6Addr::is_loopback))
1395     /// - IPv4-mapped addresses
1396     /// - Addresses reserved for benchmarking
1397     /// - Addresses reserved for documentation ([`is_documentation`](Ipv6Addr::is_documentation))
1398     /// - Unique local addresses ([`is_unique_local`](Ipv6Addr::is_unique_local))
1399     /// - Unicast addresses with link-local scope ([`is_unicast_link_local`](Ipv6Addr::is_unicast_link_local))
1400     ///
1401     /// For the complete overview of which addresses are globally reachable, see the table at the [IANA IPv6 Special-Purpose Address Registry].
1402     ///
1403     /// Note that an address having global scope is not the same as being globally reachable,
1404     /// and there is no direct relation between the two concepts: There exist addresses with global scope
1405     /// that are not globally reachable (for example unique local addresses),
1406     /// and addresses that are globally reachable without having global scope
1407     /// (multicast addresses with non-global scope).
1408     ///
1409     /// [IANA IPv6 Special-Purpose Address Registry]: https://www.iana.org/assignments/iana-ipv6-special-registry/iana-ipv6-special-registry.xhtml
1410     /// [unspecified address]: Ipv6Addr::UNSPECIFIED
1411     /// [loopback address]: Ipv6Addr::LOCALHOST
1412     ///
1413     /// # Examples
1414     ///
1415     /// ```
1416     /// #![feature(ip)]
1417     ///
1418     /// use std::net::Ipv6Addr;
1419     ///
1420     /// // Most IPv6 addresses are globally reachable:
1421     /// assert_eq!(Ipv6Addr::new(0x26, 0, 0x1c9, 0, 0, 0xafc8, 0x10, 0x1).is_global(), true);
1422     ///
1423     /// // However some addresses have been assigned a special meaning
1424     /// // that makes them not globally reachable. Some examples are:
1425     ///
1426     /// // The unspecified address (`::`)
1427     /// assert_eq!(Ipv6Addr::UNSPECIFIED.is_global(), false);
1428     ///
1429     /// // The loopback address (`::1`)
1430     /// assert_eq!(Ipv6Addr::LOCALHOST.is_global(), false);
1431     ///
1432     /// // IPv4-mapped addresses (`::ffff:0:0/96`)
1433     /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0xc00a, 0x2ff).is_global(), false);
1434     ///
1435     /// // Addresses reserved for benchmarking (`2001:2::/48`)
1436     /// assert_eq!(Ipv6Addr::new(0x2001, 2, 0, 0, 0, 0, 0, 1,).is_global(), false);
1437     ///
1438     /// // Addresses reserved for documentation (`2001:db8::/32`)
1439     /// assert_eq!(Ipv6Addr::new(0x2001, 0xdb8, 0, 0, 0, 0, 0, 1).is_global(), false);
1440     ///
1441     /// // Unique local addresses (`fc00::/7`)
1442     /// assert_eq!(Ipv6Addr::new(0xfc02, 0, 0, 0, 0, 0, 0, 1).is_global(), false);
1443     ///
1444     /// // Unicast addresses with link-local scope (`fe80::/10`)
1445     /// assert_eq!(Ipv6Addr::new(0xfe81, 0, 0, 0, 0, 0, 0, 1).is_global(), false);
1446     ///
1447     /// // For a complete overview see the IANA IPv6 Special-Purpose Address Registry.
1448     /// ```
1449     #[rustc_const_unstable(feature = "const_ipv6", issue = "76205")]
1450     #[unstable(feature = "ip", issue = "27709")]
1451     #[must_use]
1452     #[inline]
1453     pub const fn is_global(&self) -> bool {
1454         !(self.is_unspecified()
1455             || self.is_loopback()
1456             // IPv4-mapped Address (`::ffff:0:0/96`)
1457             || matches!(self.segments(), [0, 0, 0, 0, 0, 0xffff, _, _])
1458             // IPv4-IPv6 Translat. (`64:ff9b:1::/48`)
1459             || matches!(self.segments(), [0x64, 0xff9b, 1, _, _, _, _, _])
1460             // Discard-Only Address Block (`100::/64`)
1461             || matches!(self.segments(), [0x100, 0, 0, 0, _, _, _, _])
1462             // IETF Protocol Assignments (`2001::/23`)
1463             || (matches!(self.segments(), [0x2001, b, _, _, _, _, _, _] if b < 0x200)
1464                 && !(
1465                     // Port Control Protocol Anycast (`2001:1::1`)
1466                     u128::from_be_bytes(self.octets()) == 0x2001_0001_0000_0000_0000_0000_0000_0001
1467                     // Traversal Using Relays around NAT Anycast (`2001:1::2`)
1468                     || u128::from_be_bytes(self.octets()) == 0x2001_0001_0000_0000_0000_0000_0000_0002
1469                     // AMT (`2001:3::/32`)
1470                     || matches!(self.segments(), [0x2001, 3, _, _, _, _, _, _])
1471                     // AS112-v6 (`2001:4:112::/48`)
1472                     || matches!(self.segments(), [0x2001, 4, 0x112, _, _, _, _, _])
1473                     // ORCHIDv2 (`2001:20::/28`)
1474                     || matches!(self.segments(), [0x2001, b, _, _, _, _, _, _] if b >= 0x20 && b <= 0x2F)
1475                 ))
1476             || self.is_documentation()
1477             || self.is_unique_local()
1478             || self.is_unicast_link_local())
1479     }
1480
1481     /// Returns [`true`] if this is a unique local address (`fc00::/7`).
1482     ///
1483     /// This property is defined in [IETF RFC 4193].
1484     ///
1485     /// [IETF RFC 4193]: https://tools.ietf.org/html/rfc4193
1486     ///
1487     /// # Examples
1488     ///
1489     /// ```
1490     /// #![feature(ip)]
1491     ///
1492     /// use std::net::Ipv6Addr;
1493     ///
1494     /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0xc00a, 0x2ff).is_unique_local(), false);
1495     /// assert_eq!(Ipv6Addr::new(0xfc02, 0, 0, 0, 0, 0, 0, 0).is_unique_local(), true);
1496     /// ```
1497     #[rustc_const_unstable(feature = "const_ipv6", issue = "76205")]
1498     #[unstable(feature = "ip", issue = "27709")]
1499     #[must_use]
1500     #[inline]
1501     pub const fn is_unique_local(&self) -> bool {
1502         (self.segments()[0] & 0xfe00) == 0xfc00
1503     }
1504
1505     /// Returns [`true`] if this is a unicast address, as defined by [IETF RFC 4291].
1506     /// Any address that is not a [multicast address] (`ff00::/8`) is unicast.
1507     ///
1508     /// [IETF RFC 4291]: https://tools.ietf.org/html/rfc4291
1509     /// [multicast address]: Ipv6Addr::is_multicast
1510     ///
1511     /// # Examples
1512     ///
1513     /// ```
1514     /// #![feature(ip)]
1515     ///
1516     /// use std::net::Ipv6Addr;
1517     ///
1518     /// // The unspecified and loopback addresses are unicast.
1519     /// assert_eq!(Ipv6Addr::UNSPECIFIED.is_unicast(), true);
1520     /// assert_eq!(Ipv6Addr::LOCALHOST.is_unicast(), true);
1521     ///
1522     /// // Any address that is not a multicast address (`ff00::/8`) is unicast.
1523     /// assert_eq!(Ipv6Addr::new(0x2001, 0xdb8, 0, 0, 0, 0, 0, 0).is_unicast(), true);
1524     /// assert_eq!(Ipv6Addr::new(0xff00, 0, 0, 0, 0, 0, 0, 0).is_unicast(), false);
1525     /// ```
1526     #[rustc_const_unstable(feature = "const_ipv6", issue = "76205")]
1527     #[unstable(feature = "ip", issue = "27709")]
1528     #[must_use]
1529     #[inline]
1530     pub const fn is_unicast(&self) -> bool {
1531         !self.is_multicast()
1532     }
1533
1534     /// Returns `true` if the address is a unicast address with link-local scope,
1535     /// as defined in [RFC 4291].
1536     ///
1537     /// A unicast address has link-local scope if it has the prefix `fe80::/10`, as per [RFC 4291 section 2.4].
1538     /// Note that this encompasses more addresses than those defined in [RFC 4291 section 2.5.6],
1539     /// which describes "Link-Local IPv6 Unicast Addresses" as having the following stricter format:
1540     ///
1541     /// ```text
1542     /// | 10 bits  |         54 bits         |          64 bits           |
1543     /// +----------+-------------------------+----------------------------+
1544     /// |1111111010|           0             |       interface ID         |
1545     /// +----------+-------------------------+----------------------------+
1546     /// ```
1547     /// So while currently the only addresses with link-local scope an application will encounter are all in `fe80::/64`,
1548     /// this might change in the future with the publication of new standards. More addresses in `fe80::/10` could be allocated,
1549     /// and those addresses will have link-local scope.
1550     ///
1551     /// Also note that while [RFC 4291 section 2.5.3] mentions about the [loopback address] (`::1`) that "it is treated as having Link-Local scope",
1552     /// this does not mean that the loopback address actually has link-local scope and this method will return `false` on it.
1553     ///
1554     /// [RFC 4291]: https://tools.ietf.org/html/rfc4291
1555     /// [RFC 4291 section 2.4]: https://tools.ietf.org/html/rfc4291#section-2.4
1556     /// [RFC 4291 section 2.5.3]: https://tools.ietf.org/html/rfc4291#section-2.5.3
1557     /// [RFC 4291 section 2.5.6]: https://tools.ietf.org/html/rfc4291#section-2.5.6
1558     /// [loopback address]: Ipv6Addr::LOCALHOST
1559     ///
1560     /// # Examples
1561     ///
1562     /// ```
1563     /// #![feature(ip)]
1564     ///
1565     /// use std::net::Ipv6Addr;
1566     ///
1567     /// // The loopback address (`::1`) does not actually have link-local scope.
1568     /// assert_eq!(Ipv6Addr::LOCALHOST.is_unicast_link_local(), false);
1569     ///
1570     /// // Only addresses in `fe80::/10` have link-local scope.
1571     /// assert_eq!(Ipv6Addr::new(0x2001, 0xdb8, 0, 0, 0, 0, 0, 0).is_unicast_link_local(), false);
1572     /// assert_eq!(Ipv6Addr::new(0xfe80, 0, 0, 0, 0, 0, 0, 0).is_unicast_link_local(), true);
1573     ///
1574     /// // Addresses outside the stricter `fe80::/64` also have link-local scope.
1575     /// assert_eq!(Ipv6Addr::new(0xfe80, 0, 0, 1, 0, 0, 0, 0).is_unicast_link_local(), true);
1576     /// assert_eq!(Ipv6Addr::new(0xfe81, 0, 0, 0, 0, 0, 0, 0).is_unicast_link_local(), true);
1577     /// ```
1578     #[rustc_const_unstable(feature = "const_ipv6", issue = "76205")]
1579     #[unstable(feature = "ip", issue = "27709")]
1580     #[must_use]
1581     #[inline]
1582     pub const fn is_unicast_link_local(&self) -> bool {
1583         (self.segments()[0] & 0xffc0) == 0xfe80
1584     }
1585
1586     /// Returns [`true`] if this is an address reserved for documentation
1587     /// (`2001:db8::/32`).
1588     ///
1589     /// This property is defined in [IETF RFC 3849].
1590     ///
1591     /// [IETF RFC 3849]: https://tools.ietf.org/html/rfc3849
1592     ///
1593     /// # Examples
1594     ///
1595     /// ```
1596     /// #![feature(ip)]
1597     ///
1598     /// use std::net::Ipv6Addr;
1599     ///
1600     /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0xc00a, 0x2ff).is_documentation(), false);
1601     /// assert_eq!(Ipv6Addr::new(0x2001, 0xdb8, 0, 0, 0, 0, 0, 0).is_documentation(), true);
1602     /// ```
1603     #[rustc_const_unstable(feature = "const_ipv6", issue = "76205")]
1604     #[unstable(feature = "ip", issue = "27709")]
1605     #[must_use]
1606     #[inline]
1607     pub const fn is_documentation(&self) -> bool {
1608         (self.segments()[0] == 0x2001) && (self.segments()[1] == 0xdb8)
1609     }
1610
1611     /// Returns [`true`] if this is an address reserved for benchmarking (`2001:2::/48`).
1612     ///
1613     /// This property is defined in [IETF RFC 5180], where it is mistakenly specified as covering the range `2001:0200::/48`.
1614     /// This is corrected in [IETF RFC Errata 1752] to `2001:0002::/48`.
1615     ///
1616     /// [IETF RFC 5180]: https://tools.ietf.org/html/rfc5180
1617     /// [IETF RFC Errata 1752]: https://www.rfc-editor.org/errata_search.php?eid=1752
1618     ///
1619     /// ```
1620     /// #![feature(ip)]
1621     ///
1622     /// use std::net::Ipv6Addr;
1623     ///
1624     /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0xc613, 0x0).is_benchmarking(), false);
1625     /// assert_eq!(Ipv6Addr::new(0x2001, 0x2, 0, 0, 0, 0, 0, 0).is_benchmarking(), true);
1626     /// ```
1627     #[unstable(feature = "ip", issue = "27709")]
1628     #[must_use]
1629     #[inline]
1630     pub const fn is_benchmarking(&self) -> bool {
1631         (self.segments()[0] == 0x2001) && (self.segments()[1] == 0x2) && (self.segments()[2] == 0)
1632     }
1633
1634     /// Returns [`true`] if the address is a globally routable unicast address.
1635     ///
1636     /// The following return false:
1637     ///
1638     /// - the loopback address
1639     /// - the link-local addresses
1640     /// - unique local addresses
1641     /// - the unspecified address
1642     /// - the address range reserved for documentation
1643     ///
1644     /// This method returns [`true`] for site-local addresses as per [RFC 4291 section 2.5.7]
1645     ///
1646     /// ```no_rust
1647     /// The special behavior of [the site-local unicast] prefix defined in [RFC3513] must no longer
1648     /// be supported in new implementations (i.e., new implementations must treat this prefix as
1649     /// Global Unicast).
1650     /// ```
1651     ///
1652     /// [RFC 4291 section 2.5.7]: https://tools.ietf.org/html/rfc4291#section-2.5.7
1653     ///
1654     /// # Examples
1655     ///
1656     /// ```
1657     /// #![feature(ip)]
1658     ///
1659     /// use std::net::Ipv6Addr;
1660     ///
1661     /// assert_eq!(Ipv6Addr::new(0x2001, 0xdb8, 0, 0, 0, 0, 0, 0).is_unicast_global(), false);
1662     /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0xc00a, 0x2ff).is_unicast_global(), true);
1663     /// ```
1664     #[rustc_const_unstable(feature = "const_ipv6", issue = "76205")]
1665     #[unstable(feature = "ip", issue = "27709")]
1666     #[must_use]
1667     #[inline]
1668     pub const fn is_unicast_global(&self) -> bool {
1669         self.is_unicast()
1670             && !self.is_loopback()
1671             && !self.is_unicast_link_local()
1672             && !self.is_unique_local()
1673             && !self.is_unspecified()
1674             && !self.is_documentation()
1675             && !self.is_benchmarking()
1676     }
1677
1678     /// Returns the address's multicast scope if the address is multicast.
1679     ///
1680     /// # Examples
1681     ///
1682     /// ```
1683     /// #![feature(ip)]
1684     ///
1685     /// use std::net::{Ipv6Addr, Ipv6MulticastScope};
1686     ///
1687     /// assert_eq!(
1688     ///     Ipv6Addr::new(0xff0e, 0, 0, 0, 0, 0, 0, 0).multicast_scope(),
1689     ///     Some(Ipv6MulticastScope::Global)
1690     /// );
1691     /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0xc00a, 0x2ff).multicast_scope(), None);
1692     /// ```
1693     #[rustc_const_unstable(feature = "const_ipv6", issue = "76205")]
1694     #[unstable(feature = "ip", issue = "27709")]
1695     #[must_use]
1696     #[inline]
1697     pub const fn multicast_scope(&self) -> Option<Ipv6MulticastScope> {
1698         if self.is_multicast() {
1699             match self.segments()[0] & 0x000f {
1700                 1 => Some(Ipv6MulticastScope::InterfaceLocal),
1701                 2 => Some(Ipv6MulticastScope::LinkLocal),
1702                 3 => Some(Ipv6MulticastScope::RealmLocal),
1703                 4 => Some(Ipv6MulticastScope::AdminLocal),
1704                 5 => Some(Ipv6MulticastScope::SiteLocal),
1705                 8 => Some(Ipv6MulticastScope::OrganizationLocal),
1706                 14 => Some(Ipv6MulticastScope::Global),
1707                 _ => None,
1708             }
1709         } else {
1710             None
1711         }
1712     }
1713
1714     /// Returns [`true`] if this is a multicast address (`ff00::/8`).
1715     ///
1716     /// This property is defined by [IETF RFC 4291].
1717     ///
1718     /// [IETF RFC 4291]: https://tools.ietf.org/html/rfc4291
1719     ///
1720     /// # Examples
1721     ///
1722     /// ```
1723     /// use std::net::Ipv6Addr;
1724     ///
1725     /// assert_eq!(Ipv6Addr::new(0xff00, 0, 0, 0, 0, 0, 0, 0).is_multicast(), true);
1726     /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0xc00a, 0x2ff).is_multicast(), false);
1727     /// ```
1728     #[rustc_const_stable(feature = "const_ip_50", since = "1.50.0")]
1729     #[stable(since = "1.7.0", feature = "ip_17")]
1730     #[must_use]
1731     #[inline]
1732     pub const fn is_multicast(&self) -> bool {
1733         (self.segments()[0] & 0xff00) == 0xff00
1734     }
1735
1736     /// Converts this address to an [`IPv4` address] if it's an [IPv4-mapped] address,
1737     /// as defined in [IETF RFC 4291 section 2.5.5.2], otherwise returns [`None`].
1738     ///
1739     /// `::ffff:a.b.c.d` becomes `a.b.c.d`.
1740     /// All addresses *not* starting with `::ffff` will return `None`.
1741     ///
1742     /// [`IPv4` address]: Ipv4Addr
1743     /// [IPv4-mapped]: Ipv6Addr
1744     /// [IETF RFC 4291 section 2.5.5.2]: https://tools.ietf.org/html/rfc4291#section-2.5.5.2
1745     ///
1746     /// # Examples
1747     ///
1748     /// ```
1749     /// use std::net::{Ipv4Addr, Ipv6Addr};
1750     ///
1751     /// assert_eq!(Ipv6Addr::new(0xff00, 0, 0, 0, 0, 0, 0, 0).to_ipv4_mapped(), None);
1752     /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0xc00a, 0x2ff).to_ipv4_mapped(),
1753     ///            Some(Ipv4Addr::new(192, 10, 2, 255)));
1754     /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1).to_ipv4_mapped(), None);
1755     /// ```
1756     #[inline]
1757     #[must_use = "this returns the result of the operation, \
1758                   without modifying the original"]
1759     #[stable(feature = "ipv6_to_ipv4_mapped", since = "1.63.0")]
1760     #[rustc_const_stable(feature = "const_ipv6_to_ipv4_mapped", since = "1.75.0")]
1761     pub const fn to_ipv4_mapped(&self) -> Option<Ipv4Addr> {
1762         match self.octets() {
1763             [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff, a, b, c, d] => {
1764                 Some(Ipv4Addr::new(a, b, c, d))
1765             }
1766             _ => None,
1767         }
1768     }
1769
1770     /// Converts this address to an [`IPv4` address] if it is either
1771     /// an [IPv4-compatible] address as defined in [IETF RFC 4291 section 2.5.5.1],
1772     /// or an [IPv4-mapped] address as defined in [IETF RFC 4291 section 2.5.5.2],
1773     /// otherwise returns [`None`].
1774     ///
1775     /// Note that this will return an [`IPv4` address] for the IPv6 loopback address `::1`. Use
1776     /// [`Ipv6Addr::to_ipv4_mapped`] to avoid this.
1777     ///
1778     /// `::a.b.c.d` and `::ffff:a.b.c.d` become `a.b.c.d`. `::1` becomes `0.0.0.1`.
1779     /// All addresses *not* starting with either all zeroes or `::ffff` will return `None`.
1780     ///
1781     /// [`IPv4` address]: Ipv4Addr
1782     /// [IPv4-compatible]: Ipv6Addr#ipv4-compatible-ipv6-addresses
1783     /// [IPv4-mapped]: Ipv6Addr#ipv4-mapped-ipv6-addresses
1784     /// [IETF RFC 4291 section 2.5.5.1]: https://tools.ietf.org/html/rfc4291#section-2.5.5.1
1785     /// [IETF RFC 4291 section 2.5.5.2]: https://tools.ietf.org/html/rfc4291#section-2.5.5.2
1786     ///
1787     /// # Examples
1788     ///
1789     /// ```
1790     /// use std::net::{Ipv4Addr, Ipv6Addr};
1791     ///
1792     /// assert_eq!(Ipv6Addr::new(0xff00, 0, 0, 0, 0, 0, 0, 0).to_ipv4(), None);
1793     /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0xc00a, 0x2ff).to_ipv4(),
1794     ///            Some(Ipv4Addr::new(192, 10, 2, 255)));
1795     /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1).to_ipv4(),
1796     ///            Some(Ipv4Addr::new(0, 0, 0, 1)));
1797     /// ```
1798     #[rustc_const_stable(feature = "const_ip_50", since = "1.50.0")]
1799     #[stable(feature = "rust1", since = "1.0.0")]
1800     #[must_use = "this returns the result of the operation, \
1801                   without modifying the original"]
1802     #[inline]
1803     pub const fn to_ipv4(&self) -> Option<Ipv4Addr> {
1804         if let [0, 0, 0, 0, 0, 0 | 0xffff, ab, cd] = self.segments() {
1805             let [a, b] = ab.to_be_bytes();
1806             let [c, d] = cd.to_be_bytes();
1807             Some(Ipv4Addr::new(a, b, c, d))
1808         } else {
1809             None
1810         }
1811     }
1812
1813     /// Converts this address to an `IpAddr::V4` if it is an IPv4-mapped addresses, otherwise it
1814     /// returns self wrapped in an `IpAddr::V6`.
1815     ///
1816     /// # Examples
1817     ///
1818     /// ```
1819     /// #![feature(ip)]
1820     /// use std::net::Ipv6Addr;
1821     ///
1822     /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0x7f00, 0x1).is_loopback(), false);
1823     /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0x7f00, 0x1).to_canonical().is_loopback(), true);
1824     /// ```
1825     #[inline]
1826     #[must_use = "this returns the result of the operation, \
1827                   without modifying the original"]
1828     #[stable(feature = "ip_to_canonical", since = "1.75.0")]
1829     #[rustc_const_stable(feature = "ip_to_canonical", since = "1.75.0")]
1830     pub const fn to_canonical(&self) -> IpAddr {
1831         if let Some(mapped) = self.to_ipv4_mapped() {
1832             return IpAddr::V4(mapped);
1833         }
1834         IpAddr::V6(*self)
1835     }
1836
1837     /// Returns the sixteen eight-bit integers the IPv6 address consists of.
1838     ///
1839     /// ```
1840     /// use std::net::Ipv6Addr;
1841     ///
1842     /// assert_eq!(Ipv6Addr::new(0xff00, 0, 0, 0, 0, 0, 0, 0).octets(),
1843     ///            [255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]);
1844     /// ```
1845     #[rustc_const_stable(feature = "const_ip_32", since = "1.32.0")]
1846     #[stable(feature = "ipv6_to_octets", since = "1.12.0")]
1847     #[must_use]
1848     #[inline]
1849     pub const fn octets(&self) -> [u8; 16] {
1850         self.octets
1851     }
1852 }
1853
1854 /// Write an Ipv6Addr, conforming to the canonical style described by
1855 /// [RFC 5952](https://tools.ietf.org/html/rfc5952).
1856 #[stable(feature = "rust1", since = "1.0.0")]
1857 impl fmt::Display for Ipv6Addr {
1858     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1859         // If there are no alignment requirements, write the IP address directly to `f`.
1860         // Otherwise, write it to a local buffer and then use `f.pad`.
1861         if f.precision().is_none() && f.width().is_none() {
1862             let segments = self.segments();
1863
1864             if let Some(ipv4) = self.to_ipv4_mapped() {
1865                 write!(f, "::ffff:{}", ipv4)
1866             } else {
1867                 #[derive(Copy, Clone, Default)]
1868                 struct Span {
1869                     start: usize,
1870                     len: usize,
1871                 }
1872
1873                 // Find the inner 0 span
1874                 let zeroes = {
1875                     let mut longest = Span::default();
1876                     let mut current = Span::default();
1877
1878                     for (i, &segment) in segments.iter().enumerate() {
1879                         if segment == 0 {
1880                             if current.len == 0 {
1881                                 current.start = i;
1882                             }
1883
1884                             current.len += 1;
1885
1886                             if current.len > longest.len {
1887                                 longest = current;
1888                             }
1889                         } else {
1890                             current = Span::default();
1891                         }
1892                     }
1893
1894                     longest
1895                 };
1896
1897                 /// Write a colon-separated part of the address
1898                 #[inline]
1899                 fn fmt_subslice(f: &mut fmt::Formatter<'_>, chunk: &[u16]) -> fmt::Result {
1900                     if let Some((first, tail)) = chunk.split_first() {
1901                         write!(f, "{:x}", first)?;
1902                         for segment in tail {
1903                             f.write_char(':')?;
1904                             write!(f, "{:x}", segment)?;
1905                         }
1906                     }
1907                     Ok(())
1908                 }
1909
1910                 if zeroes.len > 1 {
1911                     fmt_subslice(f, &segments[..zeroes.start])?;
1912                     f.write_str("::")?;
1913                     fmt_subslice(f, &segments[zeroes.start + zeroes.len..])
1914                 } else {
1915                     fmt_subslice(f, &segments)
1916                 }
1917             }
1918         } else {
1919             const LONGEST_IPV6_ADDR: &str = "ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff";
1920
1921             let mut buf = DisplayBuffer::<{ LONGEST_IPV6_ADDR.len() }>::new();
1922             // Buffer is long enough for the longest possible IPv6 address, so this should never fail.
1923             write!(buf, "{}", self).unwrap();
1924
1925             f.pad(buf.as_str())
1926         }
1927     }
1928 }
1929
1930 #[stable(feature = "rust1", since = "1.0.0")]
1931 impl fmt::Debug for Ipv6Addr {
1932     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
1933         fmt::Display::fmt(self, fmt)
1934     }
1935 }
1936
1937 #[stable(feature = "ip_cmp", since = "1.16.0")]
1938 impl PartialEq<IpAddr> for Ipv6Addr {
1939     #[inline]
1940     fn eq(&self, other: &IpAddr) -> bool {
1941         match other {
1942             IpAddr::V4(_) => false,
1943             IpAddr::V6(v6) => self == v6,
1944         }
1945     }
1946 }
1947
1948 #[stable(feature = "ip_cmp", since = "1.16.0")]
1949 impl PartialEq<Ipv6Addr> for IpAddr {
1950     #[inline]
1951     fn eq(&self, other: &Ipv6Addr) -> bool {
1952         match self {
1953             IpAddr::V4(_) => false,
1954             IpAddr::V6(v6) => v6 == other,
1955         }
1956     }
1957 }
1958
1959 #[stable(feature = "rust1", since = "1.0.0")]
1960 impl PartialOrd for Ipv6Addr {
1961     #[inline]
1962     fn partial_cmp(&self, other: &Ipv6Addr) -> Option<Ordering> {
1963         Some(self.cmp(other))
1964     }
1965 }
1966
1967 #[stable(feature = "ip_cmp", since = "1.16.0")]
1968 impl PartialOrd<Ipv6Addr> for IpAddr {
1969     #[inline]
1970     fn partial_cmp(&self, other: &Ipv6Addr) -> Option<Ordering> {
1971         match self {
1972             IpAddr::V4(_) => Some(Ordering::Less),
1973             IpAddr::V6(v6) => v6.partial_cmp(other),
1974         }
1975     }
1976 }
1977
1978 #[stable(feature = "ip_cmp", since = "1.16.0")]
1979 impl PartialOrd<IpAddr> for Ipv6Addr {
1980     #[inline]
1981     fn partial_cmp(&self, other: &IpAddr) -> Option<Ordering> {
1982         match other {
1983             IpAddr::V4(_) => Some(Ordering::Greater),
1984             IpAddr::V6(v6) => self.partial_cmp(v6),
1985         }
1986     }
1987 }
1988
1989 #[stable(feature = "rust1", since = "1.0.0")]
1990 impl Ord for Ipv6Addr {
1991     #[inline]
1992     fn cmp(&self, other: &Ipv6Addr) -> Ordering {
1993         self.segments().cmp(&other.segments())
1994     }
1995 }
1996
1997 #[stable(feature = "i128", since = "1.26.0")]
1998 impl From<Ipv6Addr> for u128 {
1999     /// Uses [`Ipv6Addr::to_bits`] to convert an IPv6 address to a host byte order `u128`.
2000     #[inline]
2001     fn from(ip: Ipv6Addr) -> u128 {
2002         ip.to_bits()
2003     }
2004 }
2005 #[stable(feature = "i128", since = "1.26.0")]
2006 impl From<u128> for Ipv6Addr {
2007     /// Uses [`Ipv6Addr::from_bits`] to convert a host byte order `u128` to an IPv6 address.
2008     #[inline]
2009     fn from(ip: u128) -> Ipv6Addr {
2010         Ipv6Addr::from_bits(ip)
2011     }
2012 }
2013
2014 #[stable(feature = "ipv6_from_octets", since = "1.9.0")]
2015 impl From<[u8; 16]> for Ipv6Addr {
2016     /// Creates an `Ipv6Addr` from a sixteen element byte array.
2017     ///
2018     /// # Examples
2019     ///
2020     /// ```
2021     /// use std::net::Ipv6Addr;
2022     ///
2023     /// let addr = Ipv6Addr::from([
2024     ///     25u8, 24u8, 23u8, 22u8, 21u8, 20u8, 19u8, 18u8,
2025     ///     17u8, 16u8, 15u8, 14u8, 13u8, 12u8, 11u8, 10u8,
2026     /// ]);
2027     /// assert_eq!(
2028     ///     Ipv6Addr::new(
2029     ///         0x1918, 0x1716,
2030     ///         0x1514, 0x1312,
2031     ///         0x1110, 0x0f0e,
2032     ///         0x0d0c, 0x0b0a
2033     ///     ),
2034     ///     addr
2035     /// );
2036     /// ```
2037     #[inline]
2038     fn from(octets: [u8; 16]) -> Ipv6Addr {
2039         Ipv6Addr { octets }
2040     }
2041 }
2042
2043 #[stable(feature = "ipv6_from_segments", since = "1.16.0")]
2044 impl From<[u16; 8]> for Ipv6Addr {
2045     /// Creates an `Ipv6Addr` from an eight element 16-bit array.
2046     ///
2047     /// # Examples
2048     ///
2049     /// ```
2050     /// use std::net::Ipv6Addr;
2051     ///
2052     /// let addr = Ipv6Addr::from([
2053     ///     525u16, 524u16, 523u16, 522u16,
2054     ///     521u16, 520u16, 519u16, 518u16,
2055     /// ]);
2056     /// assert_eq!(
2057     ///     Ipv6Addr::new(
2058     ///         0x20d, 0x20c,
2059     ///         0x20b, 0x20a,
2060     ///         0x209, 0x208,
2061     ///         0x207, 0x206
2062     ///     ),
2063     ///     addr
2064     /// );
2065     /// ```
2066     #[inline]
2067     fn from(segments: [u16; 8]) -> Ipv6Addr {
2068         let [a, b, c, d, e, f, g, h] = segments;
2069         Ipv6Addr::new(a, b, c, d, e, f, g, h)
2070     }
2071 }
2072
2073 #[stable(feature = "ip_from_slice", since = "1.17.0")]
2074 impl From<[u8; 16]> for IpAddr {
2075     /// Creates an `IpAddr::V6` from a sixteen element byte array.
2076     ///
2077     /// # Examples
2078     ///
2079     /// ```
2080     /// use std::net::{IpAddr, Ipv6Addr};
2081     ///
2082     /// let addr = IpAddr::from([
2083     ///     25u8, 24u8, 23u8, 22u8, 21u8, 20u8, 19u8, 18u8,
2084     ///     17u8, 16u8, 15u8, 14u8, 13u8, 12u8, 11u8, 10u8,
2085     /// ]);
2086     /// assert_eq!(
2087     ///     IpAddr::V6(Ipv6Addr::new(
2088     ///         0x1918, 0x1716,
2089     ///         0x1514, 0x1312,
2090     ///         0x1110, 0x0f0e,
2091     ///         0x0d0c, 0x0b0a
2092     ///     )),
2093     ///     addr
2094     /// );
2095     /// ```
2096     #[inline]
2097     fn from(octets: [u8; 16]) -> IpAddr {
2098         IpAddr::V6(Ipv6Addr::from(octets))
2099     }
2100 }
2101
2102 #[stable(feature = "ip_from_slice", since = "1.17.0")]
2103 impl From<[u16; 8]> for IpAddr {
2104     /// Creates an `IpAddr::V6` from an eight element 16-bit array.
2105     ///
2106     /// # Examples
2107     ///
2108     /// ```
2109     /// use std::net::{IpAddr, Ipv6Addr};
2110     ///
2111     /// let addr = IpAddr::from([
2112     ///     525u16, 524u16, 523u16, 522u16,
2113     ///     521u16, 520u16, 519u16, 518u16,
2114     /// ]);
2115     /// assert_eq!(
2116     ///     IpAddr::V6(Ipv6Addr::new(
2117     ///         0x20d, 0x20c,
2118     ///         0x20b, 0x20a,
2119     ///         0x209, 0x208,
2120     ///         0x207, 0x206
2121     ///     )),
2122     ///     addr
2123     /// );
2124     /// ```
2125     #[inline]
2126     fn from(segments: [u16; 8]) -> IpAddr {
2127         IpAddr::V6(Ipv6Addr::from(segments))
2128     }
2129 }
2130
2131 #[stable(feature = "ip_bitops", since = "1.75.0")]
2132 impl Not for Ipv4Addr {
2133     type Output = Ipv4Addr;
2134
2135     #[inline]
2136     fn not(mut self) -> Ipv4Addr {
2137         for octet in &mut self.octets {
2138             *octet = !*octet;
2139         }
2140         self
2141     }
2142 }
2143
2144 #[stable(feature = "ip_bitops", since = "1.75.0")]
2145 impl Not for &'_ Ipv4Addr {
2146     type Output = Ipv4Addr;
2147
2148     #[inline]
2149     fn not(self) -> Ipv4Addr {
2150         !*self
2151     }
2152 }
2153
2154 #[stable(feature = "ip_bitops", since = "1.75.0")]
2155 impl Not for Ipv6Addr {
2156     type Output = Ipv6Addr;
2157
2158     #[inline]
2159     fn not(mut self) -> Ipv6Addr {
2160         for octet in &mut self.octets {
2161             *octet = !*octet;
2162         }
2163         self
2164     }
2165 }
2166
2167 #[stable(feature = "ip_bitops", since = "1.75.0")]
2168 impl Not for &'_ Ipv6Addr {
2169     type Output = Ipv6Addr;
2170
2171     #[inline]
2172     fn not(self) -> Ipv6Addr {
2173         !*self
2174     }
2175 }
2176
2177 macro_rules! bitop_impls {
2178     ($(
2179         $(#[$attr:meta])*
2180         impl ($BitOp:ident, $BitOpAssign:ident) for $ty:ty = ($bitop:ident, $bitop_assign:ident);
2181     )*) => {
2182         $(
2183             $(#[$attr])*
2184             impl $BitOpAssign for $ty {
2185                 fn $bitop_assign(&mut self, rhs: $ty) {
2186                     for (lhs, rhs) in iter::zip(&mut self.octets, rhs.octets) {
2187                         lhs.$bitop_assign(rhs);
2188                     }
2189                 }
2190             }
2191
2192             $(#[$attr])*
2193             impl $BitOpAssign<&'_ $ty> for $ty {
2194                 fn $bitop_assign(&mut self, rhs: &'_ $ty) {
2195                     self.$bitop_assign(*rhs);
2196                 }
2197             }
2198
2199             $(#[$attr])*
2200             impl $BitOp for $ty {
2201                 type Output = $ty;
2202
2203                 #[inline]
2204                 fn $bitop(mut self, rhs: $ty) -> $ty {
2205                     self.$bitop_assign(rhs);
2206                     self
2207                 }
2208             }
2209
2210             $(#[$attr])*
2211             impl $BitOp<&'_ $ty> for $ty {
2212                 type Output = $ty;
2213
2214                 #[inline]
2215                 fn $bitop(mut self, rhs: &'_ $ty) -> $ty {
2216                     self.$bitop_assign(*rhs);
2217                     self
2218                 }
2219             }
2220
2221             $(#[$attr])*
2222             impl $BitOp<$ty> for &'_ $ty {
2223                 type Output = $ty;
2224
2225                 #[inline]
2226                 fn $bitop(self, rhs: $ty) -> $ty {
2227                     let mut lhs = *self;
2228                     lhs.$bitop_assign(rhs);
2229                     lhs
2230                 }
2231             }
2232
2233             $(#[$attr])*
2234             impl $BitOp<&'_ $ty> for &'_ $ty {
2235                 type Output = $ty;
2236
2237                 #[inline]
2238                 fn $bitop(self, rhs: &'_ $ty) -> $ty {
2239                     let mut lhs = *self;
2240                     lhs.$bitop_assign(*rhs);
2241                     lhs
2242                 }
2243             }
2244         )*
2245     };
2246 }
2247
2248 bitop_impls! {
2249     #[stable(feature = "ip_bitops", since = "1.75.0")]
2250     impl (BitAnd, BitAndAssign) for Ipv4Addr = (bitand, bitand_assign);
2251     #[stable(feature = "ip_bitops", since = "1.75.0")]
2252     impl (BitOr, BitOrAssign) for Ipv4Addr = (bitor, bitor_assign);
2253
2254     #[stable(feature = "ip_bitops", since = "1.75.0")]
2255     impl (BitAnd, BitAndAssign) for Ipv6Addr = (bitand, bitand_assign);
2256     #[stable(feature = "ip_bitops", since = "1.75.0")]
2257     impl (BitOr, BitOrAssign) for Ipv6Addr = (bitor, bitor_assign);
2258 }