Backport: Add ReleaseUnknown to safely release IUnknown* and avoid warnings when done in

noexcept context.

Backport of changeset 8286:bddda9b7df4f.

1 files changed, 17 insertions, 0 deletions

diff --git a/win32/PlatWin.h b/win32/PlatWin.h
index 2555daac0..23c889d14 100644
--- a/win32/PlatWin.h
+++ b/win32/PlatWin.h
@@ -52,6 +52,23 @@ T DLLFunction(HMODULE hModule, LPCSTR lpProcName) noexcept {
 	return fp;
 }
 
+// Release an IUnknown* and set to nullptr.
+// While IUnknown::Release must be noexcept, it isn't marked as such so produces
+// warnings which are avoided by the catch.
+template <class T>
+void ReleaseUnknown(T *&ppUnknown) noexcept {
+	if (ppUnknown) {
+		try {
+			ppUnknown->Release();
+		}
+		catch (...) {
+			// Never occurs
+		}
+		ppUnknown = nullptr;
+	}
+}
+
+
 UINT DpiForWindow(WindowID wid) noexcept;
 
 int SystemMetricsForDpi(int nIndex, UINT dpi) noexcept;