On Saturday, 21 May 2016 at 01:09:42 UTC, Alex Parrill wrote:
On Friday, 20 May 2016 at 22:10:51 UTC, tsbockman wrote:
If that's not a satisfactory answer, please show some specific
examples of code that you don't know how to make work without
VK_NULL_HANDLE so that I can propose a workaround.
Because, as I mentioned in the OP, for VK_NULL_HANDLE to work
like it does in C on 32-bit systems, it needs to be compatible
with both pointer types (VkDevice, VkInstance, etc) and 64-bit
integer types (VkFence, VkSemaphore, many others).
That is not code. As I said, there are many possible workarounds,
but it is hard to say which is best for you without actually
seeing your code.
As an example, if VK_NULL_HANDLE only ever needs to be assigned
to opaque types on the D side (that is, types that serve only as
an ID or address for communicating with the C side), you could do
this:
private struct VkNullHandle { }
enum VK_NULL_HANDLE = VkNullHandle.init;
mixin template VkHandle(bool dispatchable) {
static if (dispatchable || (size_t.sizeof == 8))
void* bits = null;
else
ulong bits = 0;
this(typeof(this) that) {
this.bits = that.bits; }
this(VkNullHandle that) {
this.bits = typeof(this.bits).init; }
ref typeof(this) opAssign(typeof(this) that) {
this.bits = that.bits;
return this;
}
ref typeof(this) opAssign(VkNullHandle that) {
this.bits = typeof(this.bits).init;
return this;
}
}
struct VkDevice { mixin VkHandle!true; }
struct VkInstance { mixin VkHandle!true; }
struct VkFence { mixin VkHandle!false; }
struct VkSemaphore { mixin VkHandle!false; }
void main() {
VkInstance a = VK_NULL_HANDLE;
VkFence b = VK_NULL_HANDLE;
}
(DPaste: https://dpaste.dzfl.pl/8f4ce39a907f )
The above is typesafe, and can easily be made compatible with a
typical C API, since C does no parameter-related name mangling.
