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/*
Copyright ⓒ 2015 macro-attr contributors.
Licensed under the MIT license (see LICENSE or <http://opensource.org
/licenses/MIT>) or the Apache License, Version 2.0 (see LICENSE of
<http://www.apache.org/licenses/LICENSE-2.0>), at your option. All
files in the project carrying such notice may not be copied, modified,
or distributed except according to those terms.
*/
#[macro_use] extern crate macro_attr;
macro_rules! EnumIterator {
(() $(pub)* enum $name:ident { $($body:tt)* }) => {
EnumIterator! {
@collect_variants ($name),
($($body)*,) -> ()
}
};
(
@collect_variants ($name:ident),
($(,)*) -> ($($var_names:ident,)*)
) => {
type NameIter = ::std::vec::IntoIter<&'static str>;
type VariantIter = ::std::vec::IntoIter<$name>;
impl $name {
#[allow(dead_code)]
pub fn iter_variants() -> VariantIter {
vec![$($name::$var_names),*].into_iter()
}
#[allow(dead_code)]
pub fn iter_variant_names() -> NameIter {
vec![$(stringify!($var_names)),*].into_iter()
}
}
};
(
@collect_variants $fixed:tt,
($var:ident $(= $_val:expr)*, $($tail:tt)*) -> ($($var_names:tt)*)
) => {
EnumIterator! {
@collect_variants $fixed,
($($tail)*) -> ($($var_names)* $var,)
}
};
(
@collect_variants ($name:ident),
($var:ident $_struct:tt, $($tail:tt)*) -> ($($var_names:tt)*)
) => {
const _error: () = concat!(
"cannot derive EnumIterator for ",
stringify!($name),
", due to non-unitary variant ",
stringify!($var),
"."
);
};
}
macro_attr! {
#[derive(Debug, PartialEq, EnumIterator!)]
enum Get { Up, Down, AllAround }
}
#[test]
fn test_enum_iterator() {
let vs: Vec<_> = Get::iter_variant_names().zip(Get::iter_variants()).collect();
assert_eq!(&*vs, &[("Up", Get::Up), ("Down", Get::Down), ("AllAround", Get::AllAround)]);
}
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