Instance creation should have validation layers applied to it.

[jherico]

The code in vkb::Instance::Instance constructs a VkInstance and then (when either VKB_DEBUG or VKB_VALIDATION_LAYERS are defined) populates a VkDebugReportCallbackCreateInfoEXT and creates a debug report callback.

However, the VK_EXT_debug_report extension was specifically designed to ensure that validation could be applied even to instance creation.

if VKB_DEBUG or VKB_VALIDATION_LAYERS are defined, then the VkDebugReportCallbackCreateInfoEXT declaration should be before instance creation code, and the VkDebugReportCallbackCreateInfoEXT structure should be set as the pNext of VkInstanceCreateInfo