Make VK_NULL_HANDLE a pointer type.

[Ka-lua]

Please change the defintion to

enum VK_NULL_HANDLE = null;

in vkdgen.py, line 60 (was = 0 before), so that we don't get type errors when doing tests like physicalDevice == VK_NULL_HANDLE.

[ColonelThirtyTwo]

It will still produce errors on 32-bit platforms.

Non-dispatchable handles are pointers on 64-bit targets but 64-bit integers on 32-bit systems, and since D makes comparing pointers and integers a type error, such a comparison will not compile on 32-bit targets.

Since the null handle is always zero (on any sane implementation) you can just use the handles as booleans - i.e. if(handle) and if(!handle), and use SomeHandle.init if you really need a null handle value. But unfortunately, it's not possible to implement VK_NULL_HANDLE 100% correctly in D.

[ParticlePeter]

Didn't face that problem till now, but on 32-bit windows: VkDevice device = VK_NULL_HANDLE; works with enum VK_NULL_HANDLE = null; but not with enum VK_NULL_HANDLE = 0;

[ColonelThirtyTwo]

VkDevice is a dispatchable handle and thus always a pointer. Try it with, say, a VkFence.

There's unfortunately no good solution for this that works in all cases. I'm honestly considering removing VK_NULL_HANDLE (or at least deprecating it with a message) since it can hide issues in 64-bit systems.