Fix warnings and compilation on clang

cmake/CMakeLists.txt

@@ -413,9 +413,11 @@ IF(MSVC)
 		ENDIF()
 	ENDFOREACH()
 ElSE()
-    add_definitions(-Wall -Wextra -Wno-maybe-uninitialized)
+    add_definitions(-Wall -Wextra)
     if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
         add_definitions(-Wno-tautological-constant-out-of-range-compare)
+    else()
+        add_definitions(-Wno-maybe-uninitialized)
     endif()
     # -fPIC is not relevant on Windows and creates pointless warnings
     if (UNIX)

src/ifcparse/IfcFile.h

@@ -62,7 +62,9 @@ public:
 		}
 
 		bool operator!=(const type_iterator& other) const {
-			return entities_by_type_t::const_iterator::operator!=(other);
+			const entities_by_type_t::const_iterator& self_ = *this;
+			const entities_by_type_t::const_iterator& other_ = other;
+			return self_ != other_;
 		}
 	};