.. | ||
src | ||
.cargo-checksum.json | ||
build.rs | ||
Cargo.toml | ||
LICENSE-APACHE | ||
LICENSE-MIT | ||
README.md |
field-offset: safe pointer-to-member functionality
This crate implements an offset_of!(...)
macro which safely encapsulates
a pointer-to-member.
Example:
struct Foo {
x: u32,
y: f64
}
let foo_y = offset_of!(Foo => y);
let mut a = Foo { x: 1, y: 2.0 };
*foo_y.apply_mut(&mut a) = 3.0;
assert!(a.y == 3.0);
The macro returns an instance of FieldOffset<T, U>
, which represents a
pointer to a field of type U
within a containing type, T
.
The FieldOffset
type implements Add
. Applying the resulting field offset
is equivalent to applying the first field offset, then applying the second
field offset.
The macro also supports accessing nested fields:
let bar_foo_y = offset_of!(Bar => foo: Foo => y);