Macro impl_more::impl_deref_mut

macro_rules! impl_deref_mut {
    (<$($generic:ident),+> in $this:ty) => { ... };
    (<$($generic:ident),+> in $this:ty => $field:ident) => { ... };
    ($this:ty) => { ... };
    ($this:ty => $field:ident) => { ... };
}

Implement DerefMut for a struct.

The first argument is that of the struct to create the impl for and this type must also implement Deref. The second argument is required for non-newtype structs and is the field to deref to. Type parameters require special handling, see examples.

Also see impl_deref, impl_deref_and_mut, and forward_deref_and_mut.

Examples

use impl_more::{impl_deref, impl_deref_mut};

struct Foo(String);

impl_deref!(Foo => String);
impl_deref_mut!(Foo);

let mut foo = Foo("bar".to_owned());
foo.push('!');

assert_eq!(*foo, "bar!");