mew/
typemap.rs

1/// A really bad way to genericize struct fields.
2///
3/// This abomination lets you create a struct with one field per type,
4/// accessible through `as_ref()`. Internally this is just a tuple, so there is
5/// the caveat that you need to manually specify the index of each "field".
6///
7/// ```
8/// typemap! { SetOfSomeObjects =>
9///     0 SomeBindGroupLayoutOne,
10///     1 SomeOtherBindGroupTwo,
11///     2 EvenABuffer,
12///     3 AndHeresAPipeline,
13///     4 f32,
14/// }
15///
16/// let set_of_some_objects = SetOfSomeObjects(
17///     SomeBindGroupLayoutOne::new(),
18///     ...
19/// );
20///
21/// let buffer: EvenABuffer = set_of_some_objects.as_ref();
22/// let pipeline: AndHeresAPipeline = set_of_some_objects.as_ref();
23/// ```
24#[macro_export]
25macro_rules! typemap {
26    { $struct:ident =>
27        $( $num:tt $ty:ty ),* $(,)?
28    } => {
29        pub struct $struct ( $( $ty, )* );
30
31        $( impl ::std::convert::AsRef<$ty> for $struct {
32            fn as_ref(&self) -> &$ty {
33                &self.$num
34            }
35        } )*
36    }
37}
mew/typemap.rs

mew/
typemap.rs
