GCC 4.6 compatibility: no non-static member initializers.

src/Magnum/Implementation/FramebufferState.cpp

@@ -33,7 +33,10 @@
 
 namespace Magnum { namespace Implementation {
 
-constexpr const Range2Di FramebufferState::DisengagedViewport;
+#ifndef CORRADE_GCC46_COMPATIBILITY
+constexpr
+#endif
+const Range2Di FramebufferState::DisengagedViewport{{}, {-1, -1}};
 
 FramebufferState::FramebufferState(Context& context, std::vector<std::string>& extensions): readBinding{0}, drawBinding{0}, renderbufferBinding{0}, maxDrawBuffers{0}, maxColorAttachments{0}, maxRenderbufferSize{0}, maxSamples{0},
     #ifndef MAGNUM_TARGET_GLES

src/Magnum/Implementation/FramebufferState.h

@@ -43,7 +43,11 @@
 namespace Magnum { namespace Implementation {
 
 struct FramebufferState {
-    constexpr static const Range2Di DisengagedViewport{{}, {-1, -1}};
+    /* Also, GCC 4.6 doesn't have non-static member initializers */
+    #ifndef CORRADE_GCC46_COMPATIBILITY
+    constexpr
+    #endif
+    static const Range2Di DisengagedViewport;
 
     explicit FramebufferState(Context& context, std::vector<std::string>& extensions);