get_surface_capabilities2: allow p_next to be set externally

ash/src/extensions/khr/get_surface_capabilities2.rs

@@ -33,23 +33,48 @@ impl GetSurfaceCapabilities2 {
             .result_with_success(surface_capabilities)
     }
 
+    /// Retrieve the number of elements to pass to [`Self::get_physical_device_surface_formats2()`]
+    pub unsafe fn get_physical_device_surface_formats2_len(
+        &self,
+        physical_device: vk::PhysicalDevice,
+        surface_info: &vk::PhysicalDeviceSurfaceInfo2KHR,
+    ) -> VkResult<usize> {
+        let mut count = 0;
+        let err_code = self.fp.get_physical_device_surface_formats2_khr(
+            physical_device,
+            surface_info,
+            &mut count,
+            std::ptr::null_mut(),
+        );
+        err_code.result_with_success(count as usize)
+    }
+
     #[doc = "https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/vkGetPhysicalDeviceSurfaceFormats2KHR.html"]
+    ///
+    /// Call [`Self::get_physical_device_surface_formats2_len()`] to query the number of elements to pass to `out`.
+    /// Be sure to [`Default::default()`]-initialize these elements and optionally set their `p_next` pointer.
     pub unsafe fn get_physical_device_surface_formats2(
         &self,
         physical_device: vk::PhysicalDevice,
         surface_info: &vk::PhysicalDeviceSurfaceInfo2KHR,
-    ) -> VkResult<Vec<vk::SurfaceFormat2KHR>> {
-        read_into_uninitialized_vector(|count, data| {
-            self.fp.get_physical_device_surface_formats2_khr(
-                physical_device,
-                surface_info,
-                count,
-                data
-            )
-        })
+        out: &mut [vk::SurfaceFormat2KHR],
+    ) -> VkResult<()> {
+        let mut count = out.len() as u32;
+        let err_code = self.fp.get_physical_device_surface_formats2_khr(
+            physical_device,
+            surface_info,
+            &mut count,
+            out.as_mut_ptr(),
+        );
+        assert_eq!(count, out.len() as u32);
+        err_code.result()
     }
 
-    pub fn name() -> &'static CStr { vk::KhrGetSurfaceCapabilities2Fn::name() }
+    pub fn name() -> &'static CStr {
+        vk::KhrGetSurfaceCapabilities2Fn::name()
+    }
 
-    pub fn fp(&self) -> &vk::KhrGetSurfaceCapabilities2Fn { &self.fp }
+    pub fn fp(&self) -> &vk::KhrGetSurfaceCapabilities2Fn {
+        &self.fp
+    }
 }