Box is missing leak_with_allocator

[matthewpipie]

Box::leak is defined as

unsafe { &mut *Box::into_raw(b) }

However, there is no way to extract the allocator while leaking without using the underlying Box::into_raw_with_allocator, which returns (*mut T, A). I propose adding Box::leak_with_allocator, which returns (&mut T, A) by calling into_raw_with_allocator and performing the unsafe cast.

Any thoughts on this? Happy to make a PR if this is something that others think is a good idea.

[Amanieu]

Sorry for the late response. Yes! A PR would be appreciated.

[zakarumych]

This call wouldn't be safe.
Dropping allocator may effectively free the memory.
And reference would be still around.

With Global it is known that dropping allocator doesn't invalidate the memory. So Box::leak is safe.