Text: I was probably drunk or something.

This _is_ supported in GCC 4.6 and there is _nothing_ like
MAGNUM_GCC46_COMPATIBILITY since a long time.

src/Text/Text.h

@@ -40,9 +40,7 @@ class AbstractLayouter;
 class DistanceFieldGlyphCache;
 class GlyphCache;
 
-#ifndef MAGNUM_GCC46_COMPATIBILITY
 enum class Alignment: UnsignedByte;
-#endif
 
 class AbstractRenderer;
 template<UnsignedInt> class Renderer;