src/vendor/custom_derive/tests/enum_iterator.rs

   1 /*
   2 Copyright ⓒ 2015 rust-custom-derive contributors.
   3
   4 Licensed under the MIT license (see LICENSE or <http://opensource.org
   5 /licenses/MIT>) or the Apache License, Version 2.0 (see LICENSE of
   6 <http://www.apache.org/licenses/LICENSE-2.0>), at your option. All
   7 files in the project carrying such notice may not be copied, modified,
   8 or distributed except according to those terms.
   9 */
  10 #[macro_use] extern crate custom_derive;
  11
  12 macro_rules! EnumIterator {
  13     (() $(pub)* enum $name:ident { $($body:tt)* }) => {
  14         EnumIterator! {
  15             @collect_variants ($name),
  16             ($($body)*,) -> ()
  17         }
  18     };
  19
  20     (
  21         @collect_variants ($name:ident),
  22         ($(,)*) -> ($($var_names:ident,)*)
  23     ) => {
  24         type NameIter = ::std::vec::IntoIter<&'static str>;
  25         type VariantIter = ::std::vec::IntoIter<$name>;
  26
  27         impl $name {
  28             #[allow(dead_code)]
  29             pub fn iter_variants() -> VariantIter {
  30                 vec![$($name::$var_names),*].into_iter()
  31             }
  32
  33             #[allow(dead_code)]
  34             pub fn iter_variant_names() -> NameIter {
  35                 vec![$(stringify!($var_names)),*].into_iter()
  36             }
  37         }
  38     };
  39
  40     (
  41         @collect_variants $fixed:tt,
  42         ($var:ident $(= $_val:expr)*, $($tail:tt)*) -> ($($var_names:tt)*)
  43     ) => {
  44         EnumIterator! {
  45             @collect_variants $fixed,
  46             ($($tail)*) -> ($($var_names)* $var,)
  47         }
  48     };
  49
  50     (
  51         @collect_variants ($name:ident),
  52         ($var:ident $_struct:tt, $($tail:tt)*) -> ($($var_names:tt)*)
  53     ) => {
  54         const _error: () = concat!(
  55             "cannot derive EnumIterator for ",
  56             stringify!($name),
  57             ", due to non-unitary variant ",
  58             stringify!($var),
  59             "."
  60         );
  61     };
  62 }
  63
  64 custom_derive! {
  65     #[derive(Debug, PartialEq, EnumIterator)]
  66     enum Get { Up, Down, AllAround }
  67 }
  68
  69 #[test]
  70 fn test_enum_iterator() {
  71     let vs: Vec<_> = Get::iter_variant_names().zip(Get::iter_variants()).collect();
  72     assert_eq!(&*vs, &[("Up", Get::Up), ("Down", Get::Down), ("AllAround", Get::AllAround)]);
  73 }