cgt/
has.rs

1//! `Has` trait and utils
2
3/// Types that implement `Has<T>` claim to contain `T` in their structure and can give access to it
4///
5/// It is useful when different parts need to operate of a concrete part of abstract datatype.
6/// e.g. a graph vertex may have color and position, game only cares about color but layout
7/// algorithm cares only about position
8pub trait Has<T> {
9    #[allow(missing_docs)]
10    fn get_inner(&self) -> &T;
11
12    #[allow(missing_docs)]
13    fn get_inner_mut(&mut self) -> &mut T;
14}
15
16impl<T> Has<T> for T {
17    #[inline(always)]
18    fn get_inner(&self) -> &T {
19        self
20    }
21
22    #[inline(always)]
23    fn get_inner_mut(&mut self) -> &mut T {
24        self
25    }
26}
27
28/// Generate boilerplate for Has trait
29///
30/// # Examples
31/// ```rust
32/// # use cgt::impl_has;
33/// struct Foo;
34/// struct Bar {
35///     foo: Foo,
36///     bar: u32,
37/// }
38///
39/// impl_has!(Bar -> foo -> Foo);
40/// ```
41#[macro_export]
42macro_rules! impl_has {
43    ($ty:ident -> $getter:ident -> $res:ty) => {
44        impl $crate::has::Has<$res> for $ty {
45            fn get_inner(&self) -> &$res {
46                &self.$getter
47            }
48
49            fn get_inner_mut(&mut self) -> &mut $res {
50                &mut self.$getter
51            }
52        }
53    };
54}
cgt/has.rs

cgt/
has.rs
