GCC 4.4 compatibility: no explicit conversion operators.

src/Framebuffer.h

@@ -117,7 +117,11 @@ class MAGNUM_EXPORT Framebuffer: public AbstractFramebuffer {
                 inline constexpr explicit ColorAttachment(UnsignedInt id): attachment(GL_COLOR_ATTACHMENT0 + id) {}
 
                 #ifndef DOXYGEN_GENERATING_OUTPUT
+                #ifndef CORRADE_GCC44_COMPATIBILITY
                 inline constexpr explicit operator GLenum() const { return attachment; }
+                #else
+                inline constexpr operator GLenum() const { return attachment; }
+                #endif
                 #endif
 
             private:
@@ -138,7 +142,11 @@ class MAGNUM_EXPORT Framebuffer: public AbstractFramebuffer {
                 inline constexpr /*implicit*/ DrawAttachment(Framebuffer::ColorAttachment attachment): attachment(GLenum(attachment)) {}
 
                 #ifndef DOXYGEN_GENERATING_OUTPUT
+                #ifndef CORRADE_GCC44_COMPATIBILITY
                 inline constexpr explicit operator GLenum() const { return attachment; }
+                #else
+                inline constexpr operator GLenum() const { return attachment; }
+                #endif
                 #endif
 
             private:
@@ -175,7 +183,11 @@ class MAGNUM_EXPORT Framebuffer: public AbstractFramebuffer {
                 inline constexpr /*implicit*/ BufferAttachment(Framebuffer::ColorAttachment attachment): attachment(GLenum(attachment)) {}
 
                 #ifndef DOXYGEN_GENERATING_OUTPUT
+                #ifndef CORRADE_GCC44_COMPATIBILITY
                 inline constexpr explicit operator GLenum() const { return attachment; }
+                #else
+                inline constexpr operator GLenum() const { return attachment; }
+                #endif
                 #endif
 
             private:
@@ -203,7 +215,11 @@ class MAGNUM_EXPORT Framebuffer: public AbstractFramebuffer {
                 inline constexpr /*implicit*/ InvalidationAttachment(Framebuffer::ColorAttachment attachment): attachment(GLenum(attachment)) {}
 
                 #ifndef DOXYGEN_GENERATING_OUTPUT
+                #ifndef CORRADE_GCC44_COMPATIBILITY
                 inline constexpr explicit operator GLenum() const { return attachment; }
+                #else
+                inline constexpr operator GLenum() const { return attachment; }
+                #endif
                 #endif
 
             private:

src/Math/Complex.h

@@ -172,7 +172,11 @@ template<class T> class Complex {
          *      \boldsymbol v = \begin{pmatrix} a \\ b \end{pmatrix}
          * @f]
          */
+        #ifndef CORRADE_GCC44_COMPATIBILITY
         inline constexpr explicit operator Vector2<T>() const {
+        #else
+        inline constexpr operator Vector2<T>() const {
+        #endif
             return {_real, _imaginary};
         }