Add swapchain (work in progress)

src/vulkan/vk_swapchain.rs

@@ -0,0 +1,28 @@
+use ash::vk;
+
+pub struct VkSwapchain {
+    swapchain_loader: ash::khr::swapchain::Device,
+    swapchain: Option<vk::SwapchainKHR>,
+}
+
+impl VkSwapchain {
+    pub fn new(
+        swapchain_loader: ash::khr::swapchain::Device,
+        swapchain: Option<vk::SwapchainKHR>,
+    ) -> Self {
+        Self {
+            swapchain_loader,
+            swapchain
+        }
+    }
+}
+
+impl Drop for VkSwapchain {
+    fn drop(&mut self) {
+        if let Some(swapchain) = self.swapchain {
+            unsafe {
+                self.swapchain_loader.destroy_swapchain(swapchain, None);
+            }
+        }
+    }
+}