void *staging = device.get_transfer_queue().prepare_transfer(sz, [this, off, sz](VkCommandBuffer cmd_buf, VkBuffer staging_buf, size_t src_off){
const VulkanFunctions &vk = device.get_functions();
void *staging = device.get_transfer_queue().prepare_transfer(sz, [this, off, sz](VkCommandBuffer cmd_buf, VkBuffer staging_buf, size_t src_off){
const VulkanFunctions &vk = device.get_functions();