Re: Enum that can be 0 or null

[ParticlePeter via Digitalmars-d-learn]

On Monday, 6 June 2016 at 20:32:23 UTC, Alex Parrill wrote:

They'd be the same type, since you would define the vulkan functions to take these structures instead of pointer or integer types.

It relies on a lot of assumptions about the ABI that make a raw pointer work the same as a structure containing just one pointer, which is why I did not give it much consideration.

Is there a way to use opCast (just an idea, not working code) ?

private struct VK_HANDLE_HELPER {
        const void * handle = null;
        alias handle this;
        T opCast(T)() if( is( T == uint64_t )) {
                return 0uL;
        }
}
const VK_NULL_HANDLE = VK_HANDLE_HELPER();