fn realloc(self: Allocator, old_mem: anytype, new_n: usize) t: {
    const Slice = @typeInfo(@TypeOf(old_mem)).Pointer;
    break :t Error![]align(Slice.alignment) Slice.child;
}

This function requests a new byte size for an existing allocation, which can be larger, smaller, or the same size as the old memory allocation. If new_n is 0, this is the same as free and it always succeeds.

Parameters

self: Allocator,
old_mem: anytype,
new_n: usize,