impl_more/
as_ref.rs

1/// Implement [`AsRef`] for a struct.
2///
3/// The first argument is that of the struct to create the impl for and the second is the type to
4/// produce a reference for.
5///
6/// # Examples
7/// With a newtype struct:
8/// ```
9/// use impl_more::impl_as_ref;
10///
11/// struct Foo(String);
12/// impl_as_ref!(Foo => String);
13/// let foo = Foo("bar".to_owned());
14/// assert_eq!(foo.as_ref(), "bar");
15/// ```
16///
17/// With a named field struct and type parameters:
18/// ```
19/// use impl_more::impl_as_ref;
20///
21/// struct Foo<T> { inner: T }
22/// impl_as_ref!(Foo<T> => inner: T);
23/// let foo = Foo { inner: "bar".to_owned() };
24/// assert_eq!(foo.as_ref().as_str(), "bar");
25/// ```
26#[macro_export]
27macro_rules! impl_as_ref {
28    ($this:ident $(<$($generic:ident),+>)? => $inner:ty) => {
29        impl $(<$($generic),+>)? ::core::convert::AsRef<$inner> for $this $(<$($generic),+>)? {
30            fn as_ref(&self) -> &$inner {
31                &self.0
32            }
33        }
34    };
35
36    ($this:ident $(<$($generic:ident),+>)? => $field:ident : $inner:ty) => {
37        impl $(<$($generic),+>)? ::core::convert::AsRef<$inner> for $this $(<$($generic),+>)? {
38            fn as_ref(&self) -> &$inner {
39                &self.$field
40            }
41        }
42    };
43}
44
45/// Implement [`AsMut`] for a struct.
46///
47/// The first argument is that of the struct to create the impl for and the second is the type to
48/// produce a reference for.
49///
50/// # Examples
51/// With a newtype struct:
52/// ```
53/// use impl_more::{impl_as_ref, impl_as_mut};
54///
55/// struct Foo(String);
56///
57/// impl_as_ref!(Foo => String);
58/// impl_as_mut!(Foo => String);
59///
60/// let mut foo = Foo("bar".to_owned());
61/// foo.as_mut().push('!');
62///
63/// assert_eq!(foo.as_ref(), "bar!");
64/// ```
65///
66/// With a named field struct and type parameters:
67/// ```
68/// use impl_more::{impl_as_ref, impl_as_mut};
69///
70/// struct Foo<T> { inner: T }
71///
72/// impl_as_ref!(Foo<T> => inner: T);
73/// impl_as_mut!(Foo<T> => inner: T);
74///
75/// let mut foo = Foo { inner: "bar".to_owned() };
76/// foo.as_mut().push('!');
77///
78/// assert_eq!(foo.as_ref(), "bar!");
79/// ```
80#[macro_export]
81macro_rules! impl_as_mut {
82    ($this:ident $(<$($generic:ident),+>)? => $inner:ty) => {
83        impl $(<$($generic),+>)? ::core::convert::AsMut<$inner> for $this $(<$($generic),+>)? {
84            fn as_mut(&mut self) -> &mut $inner {
85                &mut self.0
86            }
87        }
88    };
89
90    ($this:ident $(<$($generic:ident),+>)? => $field:ident : $inner:ty) => {
91        impl $(<$($generic),+>)? ::core::convert::AsMut<$inner> for $this $(<$($generic),+>)? {
92            fn as_mut(&mut self) -> &mut $inner {
93                &mut self.$field
94            }
95        }
96    };
97}
impl_more/as_ref.rs

impl_more/
as_ref.rs
