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#[macro_export]
macro_rules! derive_alias {
($($name:ident => #[derive($($derive:ident),*)] $(,)?)*) => {
$(
macro_rules! $name {
($i:item) => {
#[derive($($derive),*)]
$i
}
}
)*
}
}
#[cfg(test)]
mod tests {
use std::fmt::Debug;
derive_alias! {
derive_one => #[derive(Copy, Clone, Debug)],
derive_two => #[derive(Eq, PartialEq, Ord, PartialOrd)]
}
derive_one! {
struct Foo(i32);
}
derive_two! {
struct Bar(i32);
}
#[test]
fn a_test() {
assert_impl_one(Foo(100));
assert_impl_two(Bar(200));
}
fn assert_impl_one<T>(_: T)
where
T: Copy + Clone + Debug,
{
}
fn assert_impl_two<T>(_: T)
where
T: Eq + PartialEq + Ord + PartialOrd,
{
}
#[allow(unused_macros)]
mod test_trailing_comma {
derive_alias! {
foo => #[derive()]
bar => #[derive()]
baz => #[derive()]
}
derive_alias! {
foo => #[derive()],
bar => #[derive()],
baz => #[derive()],
}
}
}