macro_rules! enum_from_primitive_impl_ty {
($meth:ident, $ty:ty, $name:ident, $( $variant:ident )*) => {
#[allow(non_upper_case_globals, unused)]
fn $meth(n: $ty) -> $crate::Option<Self> {
$( if n == $name::$variant as $ty {
$crate::Option::Some($name::$variant)
} else )* {
$crate::Option::None
}
}
};
}
macro_rules! enum_from_primitive_impl {
($name:ident, $( $variant:ident )*) => {
impl $crate::FromPrimitive for $name {
enum_from_primitive_impl_ty! { from_i64, i64, $name, $( $variant )* }
enum_from_primitive_impl_ty! { from_u64, u64, $name, $( $variant )* }
}
};
}
macro_rules! enum_from_primitive {
(
$( #[$enum_attr:meta] )*
pub enum $name:ident {
$( #[$variant_attr:meta]
$variant:ident = $discriminator:expr ),*,
}
) => {
$( #[$enum_attr] )*
pub enum $name {
$( #[$variant_attr]
$variant = $discriminator ),*,
}
enum_from_primitive_impl! { $name, $( $variant )+ }
};
}