Macro impl_more::impl_deref_and_mut
source · macro_rules! impl_deref_and_mut { (<$($generic:ident),+> in $this:ty => $target:ty) => { ... }; (<$($generic:ident),+> in $this:ty => $field:ident : $target:ty) => { ... }; ($this:ty => $target:ty) => { ... }; ($this:ty => $field:ident : $target:ty) => { ... }; }
Expand description
Implements Deref
and DerefMut
by forwarding through an inner field’s implementation.
Use the ref <type>
form for deref-ing to types with lifetimes like &str
. For newtype
structs, only the struct name and deref target type is necessary.
This macro has the same type parameter support and format as impl_deref
.
Also see forward_deref_and_mut
.
Examples
struct MyNewTypeStruct(String);
impl_more::impl_deref_and_mut!(MyNewTypeStruct => String);
let foo = MyNewTypeStruct("one".to_owned());
let foo_ref: &String = &foo;
// Unlike `forward_deref_and_mut`, this macro will not forward the deref implementation
// through the named type. Even so, in some cases Rust will be able to support these cases.
let foo_ref: &str = &foo;
fn accepts_string_slice(_: &str) {}
accepts_string_slice(&foo);