Use std::optional instead of std::unique_ptr for try_make.

This requires C++17.

2 files changed, 8 insertions, 9 deletions

diff --git a/c/defs.h b/c/defs.h
index ffebcb0..c8d76b3 100644
--- a/c/defs.h
+++ b/c/defs.h
@@ -2,6 +2,7 @@
 #define DEFS_H
 
 #include <memory>
+#include <optional>
 #include <windows.h>
 #include <commctrl.h>
 #include <SWI-Prolog.h>
@@ -144,15 +145,13 @@ inline int Dpi(int i)
 }
 
 template <class T, typename ...A>
-std::unique_ptr<T> try_make_unique(A ...args)
+std::optional<T> try_make(A ...args)
 {
-	std::unique_ptr<T> up;
 	try {
-		up = std::make_unique<T>(args...);
+		return T(args...);
 	} catch (...) {
-		up = nullptr;
+		return {};
 	}
-	return up;
 }
 
 #endif
diff --git a/c/main.cpp b/c/main.cpp
index 8bf07fb..f0adee9 100644
--- a/c/main.cpp
+++ b/c/main.cpp
@@ -35,14 +35,14 @@ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
 	LPTSTR tszErr;
 
 	/* Set constant values. */
-	if (auto upLib = try_make_unique<Library>(TEXT("uxtheme.dll")))
+	if (auto upLib = try_make<Library>(TEXT("uxtheme.dll")))
 		if (upLib->GetProcAddress("SetWindowTheme")) {
 			g_bThemes = 1;
 		}
 	g_cxVScroll = GetSystemMetrics(SM_CXVSCROLL);
 
 	/* Setup fonts. */
-	if (auto upLib = try_make_unique<Library>(TEXT("User32.dll"))) {
+	if (auto upLib = try_make<Library>(TEXT("User32.dll"))) {
 		if (upLib->GetProcAddress("SystemParametersInfo" WA)) {
 			NONCLIENTMETRICS m;
 			m.cbSize = sizeof(NONCLIENTMETRICS);
@@ -140,8 +140,8 @@ static LRESULT CALLBACK CBTProc(int nCode, WPARAM wParam, LPARAM lParam)
 	g_hWnd = (HWND)wParam;
 
 	/* Get DPI. */
-	if (auto upLib = try_make_unique<Library>(TEXT("User32.dll")))
-		if (auto GetDpiForWindow = (UINT (*)(HWND))upLib->GetProcAddress("GetDpiForWindow"))
+	if (auto opLib = try_make<Library>(TEXT("User32.dll")))
+		if (auto GetDpiForWindow = (UINT (*)(HWND))opLib->GetProcAddress("GetDpiForWindow"))
 			g_iDPI = GetDpiForWindow(g_hWnd);
 
 	/* Create child windows. */