1.0.0[−][src]Function core::mem::transmute_copy
pub unsafe fn transmute_copy<T, U>(src: &T) -> U
Interprets src
as having type &U
, and then reads src
without moving
the contained value.
This function will unsafely assume the pointer src
is valid for
size_of::<U>
bytes by transmuting &T
to &U
and then reading
the &U
. It will also unsafely create a copy of the contained value instead of
moving out of src
.
It is not a compile-time error if T
and U
have different sizes, but it
is highly encouraged to only invoke this function where T
and U
have the
same size. This function triggers undefined behavior if U
is larger than
T
.
Examples
use std::mem; #[repr(packed)] struct Foo { bar: u8, } let foo_slice = [10u8]; unsafe { // Copy the data from 'foo_slice' and treat it as a 'Foo' let mut foo_struct: Foo = mem::transmute_copy(&foo_slice); assert_eq!(foo_struct.bar, 10); // Modify the copied data foo_struct.bar = 20; assert_eq!(foo_struct.bar, 20); } // The contents of 'foo_slice' should not have changed assert_eq!(foo_slice, [10]);Run