Address warnings on Clang 3.9 caused by having a static data member in a class template.

code/BlenderBMesh.cpp

@@ -52,7 +52,11 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 namespace Assimp
 {
-    template< > const std::string LogFunctions< BlenderBMeshConverter >::log_prefix = "BLEND_BMESH: ";
+    template< > const char* LogFunctions< BlenderBMeshConverter >::Prefix()
+    {
+        static auto prefix = "BLEND_BMESH: ";
+        return prefix;
+    }
 }
 
 using namespace Assimp;

code/BlenderLoader.cpp

@@ -74,7 +74,11 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #endif
 
 namespace Assimp {
-    template<> const std::string LogFunctions<BlenderImporter>::log_prefix = "BLEND: ";
+    template<> const char* LogFunctions<BlenderImporter>::Prefix()
+    {
+        static auto prefix = "BLEND: ";
+        return prefix;
+    }
 }
 
 using namespace Assimp;

code/BlenderTessellator.cpp

@@ -59,7 +59,11 @@ static const unsigned int BLEND_TESS_MAGIC = 0x83ed9ac3;
 
 namspace Assimp
 {
-    template< > const std::string LogFunctions< BlenderTessellatorGL >::log_prefix = "BLEND_TESS_GL: ";
+    template< > const char* LogFunctions< BlenderTessellatorGL >::Prefix()
+    {
+        static auto prefix = "BLEND_TESS_GL: ";
+        return prefix;
+    }
 }
 
 using namespace Assimp;
@@ -252,7 +256,11 @@ void BlenderTessellatorGL::TessellateError( GLenum errorCode, void* )
 
 namespace Assimp
 {
-    template< > const std::string LogFunctions< BlenderTessellatorP2T >::log_prefix = "BLEND_TESS_P2T: ";
+    template< > const char* LogFunctions< BlenderTessellatorP2T >::Prefix()
+    {
+        static auto prefix = "BLEND_TESS_P2T: ";
+        return prefix;
+    }
 }
 
 using namespace Assimp;

code/FBXImporter.cpp

@@ -59,7 +59,11 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <assimp/importerdesc.h>
 
 namespace Assimp {
-    template<> const std::string LogFunctions<FBXImporter>::log_prefix = "FBX: ";
+    template<> const char* LogFunctions<FBXImporter>::Prefix()
+    {
+        static auto prefix = "FBX: ";
+        return prefix;
+    }
 }
 
 using namespace Assimp;

code/IFCLoader.cpp

@@ -66,7 +66,11 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 
 namespace Assimp {
-    template<> const std::string LogFunctions<IFCImporter>::log_prefix = "IFC: ";
+    template<> const char* LogFunctions<IFCImporter>::Prefix()
+    {
+        static auto prefix = "IFC: ";
+        return prefix;
+    }
 }
 
 using namespace Assimp;

code/LogAux.h

@@ -60,34 +60,34 @@ public:
     // ------------------------------------------------------------------------------------------------
     static void ThrowException(const std::string& msg)
     {
-        throw DeadlyImportError(log_prefix+msg);
+        throw DeadlyImportError(Prefix()+msg);
     }
 
     // ------------------------------------------------------------------------------------------------
     static void LogWarn(const Formatter::format& message)   {
         if (!DefaultLogger::isNullLogger()) {
-            DefaultLogger::get()->warn(log_prefix+(std::string)message);
+            DefaultLogger::get()->warn(Prefix() +(std::string)message);
         }
     }
 
     // ------------------------------------------------------------------------------------------------
     static void LogError(const Formatter::format& message)  {
         if (!DefaultLogger::isNullLogger()) {
-            DefaultLogger::get()->error(log_prefix+(std::string)message);
+            DefaultLogger::get()->error(Prefix() +(std::string)message);
         }
     }
 
     // ------------------------------------------------------------------------------------------------
     static void LogInfo(const Formatter::format& message)   {
         if (!DefaultLogger::isNullLogger()) {
-            DefaultLogger::get()->info(log_prefix+(std::string)message);
+            DefaultLogger::get()->info(Prefix() +(std::string)message);
         }
     }
 
     // ------------------------------------------------------------------------------------------------
     static void LogDebug(const Formatter::format& message)  {
         if (!DefaultLogger::isNullLogger()) {
-            DefaultLogger::get()->debug(log_prefix+(std::string)message);
+            DefaultLogger::get()->debug(Prefix() +(std::string)message);
         }
     }
 
@@ -125,8 +125,7 @@ public:
 #endif
 
 private:
-
-    static const std::string log_prefix;
+    static const char* Prefix();
 
 };
 

code/XGLLoader.cpp

@@ -83,8 +83,11 @@ struct free_it
 };
 
 namespace Assimp { // this has to be in here because LogFunctions is in ::Assimp
-template<> const std::string LogFunctions<XGLImporter>::log_prefix = "XGL: ";
-
+    template<> const char* LogFunctions<XGLImporter>::Prefix()
+    {
+        static auto prefix = "XGL: ";
+        return prefix;
+    }
 }
 
 static const aiImporterDesc desc = {