Use the foreach construct.

Hmm...another opportunity for smart pointers?

src/RageDisplay_OGL.cpp

@@ -748,8 +748,8 @@ RString RageDisplay_Legacy::TryVideoMode( const VideoModeParams &p, bool &bNewDe
 
 		/* Delete all render targets.  They may have associated resources other than
 		 * the texture itself. */
-		FOREACHM( unsigned, RenderTarget *, g_mapRenderTargets, rt )
-			delete rt->second;
+		for (std::pair<unsigned const, RenderTarget *> &rt : g_mapRenderTargets)
+			delete rt.second;
 		g_mapRenderTargets.clear();
 
 		/* Recreate all vertex buffers. */