KhronosGroup / KhronosGroup/Vulkan-Docs

The ordering guarantee for the returned elements of vkGetPhysicalDeviceQueueFamilyProperties

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Description

The 1.2.192 specification claims the following ordering guarantee for the returned elements of `VkPhysicalDeviceMemoryProperties`:

>
> For each pair of elements **X** and **Y** returned in `memoryTypes`, **X** must be placed at a lower index position than **Y** if:
>
> - the set of bit flags returned in the `propertyFlags` member of **X** is a strict subset of the set of bit flags returned in the `propertyFlags` member of **Y**; or
>
> - the `propertyFlags` members of **X** and **Y** are equal, and **X** belongs to a memory heap with greater performance (as determined in an implementation-specific manner)
>

What about the ordering of the returned elements of `vkGetPhysicalDeviceQueueFamilyProperties`? The specification doesn't say anything about it, though a similar guarantee would be useful - queue family selection algorithms would benefit from this. More specifically it **could** be:

>
> For each pair of elements **X** and **Y** returned in `pQueueFamilyProperties`, **X** must be placed at a lower index position than **Y** if:
>
> - the set of bit flags returned in the `queueFlags` member of **X** is a strict subset of the set of bit flags returned in the `queueFlags` member of **Y**; or
>
> - the `queueFlags` members of **X** and **Y** are equal, and **X** belongs to a queue family with greater performance (as determined in an implementation-specific manner)
>

Is it something that could be added to the specification in the future?

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