Add OVERRIDE macro, allows "override" keyword when c++11 is available

...and no errors when compiler is not capable of c++11 builds.

Author: nyalldawson

CMakeLists.txt

@@ -319,6 +319,30 @@ FIND_PROGRAM(QT_LRELEASE_EXECUTABLE
     NO_DEFAULT_PATH
     )
 
+#############################################################
+# enable use of c++11 features where available
+
+IF ("${CMAKE_CXX_COMPILER_ID}" MATCHES "GNU")
+  EXECUTE_PROCESS(COMMAND ${CMAKE_CXX_COMPILER} -dumpversion OUTPUT_VARIABLE GCC_VERSION)
+  IF (GCC_VERSION VERSION_GREATER 4.7 OR GCC_VERSION VERSION_EQUAL 4.7)
+    SET(USE_CXX_11 TRUE)
+    SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
+  ENDIF()
+ELSEIF ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
+  SET(USE_CXX_11 TRUE)
+  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
+ELSE()
+  SET(USE_CXX_11 FALSE)
+ENDIF()
+
+#allow override keyword if available
+IF (USE_CXX_11)
+  SET(OVERRIDEKEYWORD "override")
+ELSE()
+  SET(OVERRIDEKEYWORD "")
+ENDIF()
+ADD_DEFINITIONS("-DOVERRIDE=${OVERRIDEKEYWORD}")
+
 #############################################################
 # enable warnings
 

src/core/symbology-ng/qgsvectorcolorrampv2.h

@@ -70,7 +70,7 @@ class CORE_EXPORT QgsVectorGradientColorRampV2 : public QgsVectorColorRampV2
 
     virtual double value( int index ) const;
 
-    virtual QColor color( double value ) const;
+    virtual QColor color( double value ) const OVERRIDE;
 
     virtual QString type() const { return "gradient"; }