vendor/serde/src/integer128.rs

   1 /// Conditional compilation depending on whether Serde is built with support for
   2 /// 128-bit integers.
   3 ///
   4 /// Data formats that wish to support Rust compiler versions older than 1.26
   5 /// (or targets that lack 128-bit integers) may place the i128 / u128 methods
   6 /// of their Serializer and Deserializer behind this macro.
   7 ///
   8 /// Data formats that require a minimum Rust compiler version of at least 1.26,
   9 /// or do not target platforms that lack 128-bit integers, do not need to
  10 /// bother with this macro and may assume support for 128-bit integers.
  11 ///
  12 /// ```edition2018
  13 /// # use serde::private::ser::Error;
  14 /// #
  15 /// # struct MySerializer;
  16 /// #
  17 /// use serde::{serde_if_integer128, Serializer};
  18 ///
  19 /// impl Serializer for MySerializer {
  20 ///     type Ok = ();
  21 ///     type Error = Error;
  22 ///
  23 ///     fn serialize_i64(self, v: i64) -> Result<Self::Ok, Self::Error> {
  24 ///         /* ... */
  25 /// #         unimplemented!()
  26 ///     }
  27 ///
  28 ///     /* ... */
  29 ///
  30 ///     serde_if_integer128! {
  31 ///         fn serialize_i128(self, v: i128) -> Result<Self::Ok, Self::Error> {
  32 ///             /* ... */
  33 /// #             unimplemented!()
  34 ///         }
  35 ///
  36 ///         fn serialize_u128(self, v: u128) -> Result<Self::Ok, Self::Error> {
  37 ///             /* ... */
  38 /// #             unimplemented!()
  39 ///         }
  40 ///     }
  41 /// #
  42 /// #     serde::__serialize_unimplemented! {
  43 /// #         bool i8 i16 i32 u8 u16 u32 u64 f32 f64 char str bytes none some
  44 /// #         unit unit_struct unit_variant newtype_struct newtype_variant seq
  45 /// #         tuple tuple_struct tuple_variant map struct struct_variant
  46 /// #     }
  47 /// }
  48 /// ```
  49 ///
  50 /// When Serde is built with support for 128-bit integers, this macro expands
  51 /// transparently into just the input tokens.
  52 ///
  53 /// ```edition2018
  54 /// macro_rules! serde_if_integer128 {
  55 ///     ($($tt:tt)*) => {
  56 ///         $($tt)*
  57 ///     };
  58 /// }
  59 /// ```
  60 ///
  61 /// When built without support for 128-bit integers, this macro expands to
  62 /// nothing.
  63 ///
  64 /// ```edition2018
  65 /// macro_rules! serde_if_integer128 {
  66 ///     ($($tt:tt)*) => {};
  67 /// }
  68 /// ```
  69 #[cfg(integer128)]
  70 #[macro_export]
  71 macro_rules! serde_if_integer128 {
  72     ($($tt:tt)*) => {
  73         $($tt)*
  74     };
  75 }
  76
  77 #[cfg(not(integer128))]
  78 #[macro_export]
  79 #[doc(hidden)]
  80 macro_rules! serde_if_integer128 {
  81     ($($tt:tt)*) => {};
  82 }