New upstream version 1.46.0~beta.2+dfsg1

[rustc.git] / vendor / arrayvec / src / array.rs

diff --git a/vendor/arrayvec/src/array.rs b/vendor/arrayvec/src/array.rs
index 2ca90b30d5a7469cd6b68d696b4c573ac4da3475..96a8bfd284c7d582697b81b77ee81d01edc77959 100644 (file)
--- a/vendor/arrayvec/src/array.rs
+++ b/vendor/arrayvec/src/array.rs
@@ -1,36 +1,56 @@
 
 /// Trait for fixed size arrays.
+///
+/// This trait is implemented for some specific array sizes, see
+/// the implementor list below. At the current state of Rust we can't
+/// make this fully general for every array size.
+///
+/// The following crate features add more array sizes (and they are not
+/// enabled by default due to their impact on compliation speed).
+///
+/// - `array-sizes-33-128`: All sizes 33 to 128 are implemented
+///   (a few in this range are included by default).
+/// - `array-sizes-129-255`: All sizes 129 to 255 are implemented
+///   (a few in this range are included by default).
+///
+/// ## Safety
+///
+/// This trait can *only* be implemented by fixed-size arrays or types with
+/// *exactly* the representation of a fixed size array (of the right element
+/// type and capacity).
+///
+/// Normally this trait is an implementation detail of arrayvec and doesn’t
+/// need implementing.
 pub unsafe trait Array {
     /// The array’s element type
     type Item;
+    /// The smallest type that can index and tell the length of the array.
     #[doc(hidden)]
-    /// The smallest index type that indexes the array.
     type Index: Index;
-    #[doc(hidden)]
-    fn as_ptr(&self) -> *const Self::Item;
-    #[doc(hidden)]
-    fn as_mut_ptr(&mut self) -> *mut Self::Item;
-    #[doc(hidden)]
-    fn capacity() -> usize;
+    /// The array's element capacity
+    const CAPACITY: usize;
+    fn as_slice(&self) -> &[Self::Item];
+    fn as_mut_slice(&mut self) -> &mut [Self::Item];
 }
 
 pub trait Index : PartialEq + Copy {
     fn to_usize(self) -> usize;
-    fn from(usize) -> Self;
+    fn from(_: usize) -> Self;
 }
 
-use std::slice::{from_raw_parts};
-
-pub trait ArrayExt : Array {
+impl Index for () {
     #[inline(always)]
-    fn as_slice(&self) -> &[Self::Item] {
-        unsafe {
-            from_raw_parts(self.as_ptr(), Self::capacity())
-        }
-    }
+    fn to_usize(self) -> usize { 0 }
+    #[inline(always)]
+    fn from(_ix: usize) ->  Self { () }
 }
 
-impl<A> ArrayExt for A where A: Array { }
+impl Index for bool {
+    #[inline(always)]
+    fn to_usize(self) -> usize { self as usize }
+    #[inline(always)]
+    fn from(ix: usize) ->  Self { ix != 0 }
+}
 
 impl Index for u8 {
     #[inline(always)]
@@ -65,27 +85,58 @@ macro_rules! fix_array_impl {
         unsafe impl<T> Array for [T; $len] {
             type Item = T;
             type Index = $index_type;
-            #[inline(always)]
-            fn as_ptr(&self) -> *const T { self as *const _ as *const _ }
-            #[inline(always)]
-            fn as_mut_ptr(&mut self) -> *mut T { self as *mut _ as *mut _}
-            #[inline(always)]
-            fn capacity() -> usize { $len }
+            const CAPACITY: usize = $len;
+            #[doc(hidden)]
+            fn as_slice(&self) -> &[Self::Item] { self }
+            #[doc(hidden)]
+            fn as_mut_slice(&mut self) -> &mut [Self::Item] { self }
         }
     )
 }
 
 macro_rules! fix_array_impl_recursive {
     ($index_type:ty, ) => ();
-    ($index_type:ty, $len:expr, $($more:expr,)*) => (
-        fix_array_impl!($index_type, $len);
-        fix_array_impl_recursive!($index_type, $($more,)*);
+    ($index_type:ty, $($len:expr,)*) => (
+        $(fix_array_impl!($index_type, $len);)*
     );
 }
 
-fix_array_impl_recursive!(u8, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
-                          16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
-                          32, 40, 48, 50, 56, 64, 72, 96, 100, 128, 160, 192, 200, 224,);
+
+fix_array_impl_recursive!((), 0,);
+fix_array_impl_recursive!(bool, 1,);
+fix_array_impl_recursive!(u8, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
+                          15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,
+                          28, 29, 30, 31, );
+
+#[cfg(not(feature="array-sizes-33-128"))]
+fix_array_impl_recursive!(u8, 32, 40, 48, 50, 56, 64, 72, 96, 100, 128, );
+
+#[cfg(feature="array-sizes-33-128")]
+fix_array_impl_recursive!(u8, 
+32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,
+52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71,
+72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91,
+92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108,
+109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124,
+125, 126, 127, 128,
+);
+
+#[cfg(not(feature="array-sizes-129-255"))]
+fix_array_impl_recursive!(u8, 160, 192, 200, 224,);
+
+#[cfg(feature="array-sizes-129-255")]
+fix_array_impl_recursive!(u8,
+129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140,
+141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156,
+157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172,
+173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188,
+189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204,
+205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220,
+221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236,
+237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252,
+253, 254, 255,
+);
+
 fix_array_impl_recursive!(u16, 256, 384, 512, 768, 1024, 2048, 4096, 8192, 16384, 32768,);
 // This array size doesn't exist on 16-bit
 #[cfg(any(target_pointer_width="32", target_pointer_width="64"))]