Merge pull request #1231 from dpshamonin/vs-2015-error-C2131

fix compiler (VS 2015 error C2131) issue #1226

include/igl/opengl/glfw/imgui/ImGuiTraits.h

@@ -26,42 +26,42 @@ template<>
 class ImGuiDataTypeTraits<int>
 {
 	static constexpr ImGuiDataType value = ImGuiDataType_S32;
-	static constexpr char format [] = "%d";
+	static constexpr const char *format = "%d";
 };
 
 template<>
 class ImGuiDataTypeTraits<unsigned int>
 {
 	static constexpr ImGuiDataType value = ImGuiDataType_U32;
-	static constexpr char format [] = "%u";
+	static constexpr const char *format = "%u";
 };
 
 template<>
 class ImGuiDataTypeTraits<long long>
 {
 	static constexpr ImGuiDataType value = ImGuiDataType_S64;
-	static constexpr char format [] = "%lld";
+	static constexpr const char *format = "%lld";
 };
 
 template<>
 class ImGuiDataTypeTraits<unsigned long long>
 {
 	static constexpr ImGuiDataType value = ImGuiDataType_U64;
-	static constexpr char format [] = "%llu";
+	static constexpr const char *format = "%llu";
 };
 
 template<>
 class ImGuiDataTypeTraits<float>
 {
 	static constexpr ImGuiDataType value = ImGuiDataType_Float;
-	static constexpr char format [] = "%.3f";
+	static constexpr const char *format = "%.3f";
 };
 
 template<>
 class ImGuiDataTypeTraits<double>
 {
 	static constexpr ImGuiDataType value = ImGuiDataType_Double;
-	static constexpr char format [] = "%.6f";
+	static constexpr const char *format = "%.6f";
 };
 
 } // namespace ImGui