src/librustc_metadata/macros.rs

   1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 macro_rules! enum_from_u32 {
  12     ($(#[$attr:meta])* pub enum $name:ident {
  13         $($variant:ident = $e:expr,)*
  14     }) => {
  15         $(#[$attr])*
  16         pub enum $name {
  17             $($variant = $e),*
  18         }
  19
  20         impl $name {
  21             pub fn from_u32(u: u32) -> Option<$name> {
  22                 $(if u == $name::$variant as u32 {
  23                     return Some($name::$variant)
  24                 })*
  25                 None
  26             }
  27         }
  28     };
  29     ($(#[$attr:meta])* pub enum $name:ident {
  30         $($variant:ident,)*
  31     }) => {
  32         $(#[$attr])*
  33         pub enum $name {
  34             $($variant,)*
  35         }
  36
  37         impl $name {
  38             pub fn from_u32(u: u32) -> Option<$name> {
  39                 $(if u == $name::$variant as u32 {
  40                     return Some($name::$variant)
  41                 })*
  42                 None
  43             }
  44         }
  45     }
  46 }