Function std::rt::heap::reallocateUnstable

pub unsafe fn reallocate(ptr: *mut u8, old_size: usize, size: usize, align: usize) -> *mut u8

Resize the allocation referenced by ptr to size bytes.

On failure, return a null pointer and leave the original allocation intact.

Behavior is undefined if the requested size is 0 or the alignment is not a power of 2. The alignment must be no larger than the largest supported page size on the platform.

The old_size and align parameters are the parameters that were used to create the allocation referenced by ptr. The old_size parameter may be any value in range_inclusive(requested_size, usable_size).