diff --git a/code/X3DImporter.cpp b/code/X3DImporter.cpp
index 024eedb28..8c9f75f8b 100644
--- a/code/X3DImporter.cpp
+++ b/code/X3DImporter.cpp
@@ -46,6 +46,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include "X3DImporter.hpp"
 #include "X3DImporter_Macro.hpp"
+#include "StringUtils.h"
 
 // Header files, Assimp.
 #include "DefaultIOSystem.h"
diff --git a/code/X3DImporter_Postprocess.cpp b/code/X3DImporter_Postprocess.cpp
index 37acb0fe8..95f40ef9f 100644
--- a/code/X3DImporter_Postprocess.cpp
+++ b/code/X3DImporter_Postprocess.cpp
@@ -48,6 +48,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 // Header files, Assimp.
 #include "StandardShapes.h"
+#include "StringUtils.h"
 
 // Header files, stdlib.
 #include <algorithm>
@@ -296,7 +297,7 @@ void X3DImporter::Postprocess_BuildMesh(const CX3DImporter_NodeElement& pNodeEle
 			else if((*ch_it)->Type == CX3DImporter_NodeElement::ENET_TextureCoordinate)
 				MeshGeometry_AddTexCoord(**pMesh, ((CX3DImporter_NodeElement_TextureCoordinate*)*ch_it)->Value);
 			else
-				throw DeadlyImportError("Postprocess_BuildMesh. Unknown child of ElevationGrid: " + std::to_string((*ch_it)->Type) + ".");
+				throw DeadlyImportError("Postprocess_BuildMesh. Unknown child of ElevationGrid: " + to_string((*ch_it)->Type) + ".");
 		}// for(std::list<CX3DImporter_NodeElement*>::iterator ch_it = tnemesh.Child.begin(); ch_it != tnemesh.Child.end(); ch_it++)
 
 		return;// mesh is build, nothing to do anymore.
@@ -333,7 +334,7 @@ void X3DImporter::Postprocess_BuildMesh(const CX3DImporter_NodeElement& pNodeEle
 			else if((*ch_it)->Type == CX3DImporter_NodeElement::ENET_TextureCoordinate)
 				MeshGeometry_AddTexCoord(**pMesh, tnemesh.CoordIndex, tnemesh.TexCoordIndex, ((CX3DImporter_NodeElement_TextureCoordinate*)*ch_it)->Value);
 			else
-				throw DeadlyImportError("Postprocess_BuildMesh. Unknown child of IndexedFaceSet: " + std::to_string((*ch_it)->Type) + ".");
+				throw DeadlyImportError("Postprocess_BuildMesh. Unknown child of IndexedFaceSet: " + to_string((*ch_it)->Type) + ".");
 		}// for(std::list<CX3DImporter_NodeElement*>::iterator ch_it = tnemesh.Child.begin(); ch_it != tnemesh.Child.end(); ch_it++)
 
 		return;// mesh is build, nothing to do anymore.
@@ -401,7 +402,7 @@ void X3DImporter::Postprocess_BuildMesh(const CX3DImporter_NodeElement& pNodeEle
 				MeshGeometry_AddTexCoord(**pMesh, tnemesh.CoordIndex, tnemesh.TexCoordIndex, ((CX3DImporter_NodeElement_TextureCoordinate*)*ch_it)->Value);
 			else
 				throw DeadlyImportError("Postprocess_BuildMesh. Unknown child of IndexedTriangleSet or IndexedTriangleFanSet, or \
-																	IndexedTriangleStripSet: " + std::to_string((*ch_it)->Type) + ".");
+																	IndexedTriangleStripSet: " + to_string((*ch_it)->Type) + ".");
 		}// for(std::list<CX3DImporter_NodeElement*>::iterator ch_it = tnemesh.Child.begin(); ch_it != tnemesh.Child.end(); ch_it++)
 
 		return;// mesh is build, nothing to do anymore.
@@ -451,7 +452,7 @@ void X3DImporter::Postprocess_BuildMesh(const CX3DImporter_NodeElement& pNodeEle
 			else if((*ch_it)->Type == CX3DImporter_NodeElement::ENET_Coordinate)
 				{} // skip because already read when mesh created.
 			else
-				throw DeadlyImportError("Postprocess_BuildMesh. Unknown child of PointSet: " + std::to_string((*ch_it)->Type) + ".");
+				throw DeadlyImportError("Postprocess_BuildMesh. Unknown child of PointSet: " + to_string((*ch_it)->Type) + ".");
 		}// for(std::list<CX3DImporter_NodeElement*>::iterator ch_it = tnemesh.Child.begin(); ch_it != tnemesh.Child.end(); ch_it++)
 
 		return;// mesh is build, nothing to do anymore.
@@ -480,7 +481,7 @@ void X3DImporter::Postprocess_BuildMesh(const CX3DImporter_NodeElement& pNodeEle
 			else if((*ch_it)->Type == CX3DImporter_NodeElement::ENET_Coordinate)
 				{} // skip because already read when mesh created.
 			else
-				throw DeadlyImportError("Postprocess_BuildMesh. Unknown child of LineSet: " + std::to_string((*ch_it)->Type) + ".");
+				throw DeadlyImportError("Postprocess_BuildMesh. Unknown child of LineSet: " + to_string((*ch_it)->Type) + ".");
 		}// for(std::list<CX3DImporter_NodeElement*>::iterator ch_it = tnemesh.Child.begin(); ch_it != tnemesh.Child.end(); ch_it++)
 
 		return;// mesh is build, nothing to do anymore.
@@ -514,7 +515,7 @@ void X3DImporter::Postprocess_BuildMesh(const CX3DImporter_NodeElement& pNodeEle
 			else if((*ch_it)->Type == CX3DImporter_NodeElement::ENET_TextureCoordinate)
 				MeshGeometry_AddTexCoord(**pMesh, tnemesh.CoordIndex, tnemesh.TexCoordIndex, ((CX3DImporter_NodeElement_TextureCoordinate*)*ch_it)->Value);
 			else
-				throw DeadlyImportError("Postprocess_BuildMesh. Unknown child of TrianlgeFanSet: " + std::to_string((*ch_it)->Type) + ".");
+				throw DeadlyImportError("Postprocess_BuildMesh. Unknown child of TrianlgeFanSet: " + to_string((*ch_it)->Type) + ".");
 		}// for(std::list<CX3DImporter_NodeElement*>::iterator ch_it = tnemesh.Child.begin(); ch_it != tnemesh.Child.end(); ch_it++)
 
 		return;// mesh is build, nothing to do anymore.
@@ -557,7 +558,7 @@ void X3DImporter::Postprocess_BuildMesh(const CX3DImporter_NodeElement& pNodeEle
 			else if((*ch_it)->Type == CX3DImporter_NodeElement::ENET_TextureCoordinate)
 				MeshGeometry_AddTexCoord(**pMesh, tnemesh.CoordIndex, tnemesh.TexCoordIndex, ((CX3DImporter_NodeElement_TextureCoordinate*)*ch_it)->Value);
 			else
-				throw DeadlyImportError("Postprocess_BuildMesh. Unknown child of TrianlgeSet: " + std::to_string((*ch_it)->Type) + ".");
+				throw DeadlyImportError("Postprocess_BuildMesh. Unknown child of TrianlgeSet: " + to_string((*ch_it)->Type) + ".");
 		}// for(std::list<CX3DImporter_NodeElement*>::iterator ch_it = tnemesh.Child.begin(); ch_it != tnemesh.Child.end(); ch_it++)
 
 		return;// mesh is build, nothing to do anymore.
@@ -591,13 +592,13 @@ void X3DImporter::Postprocess_BuildMesh(const CX3DImporter_NodeElement& pNodeEle
 			else if((*ch_it)->Type == CX3DImporter_NodeElement::ENET_TextureCoordinate)
 				MeshGeometry_AddTexCoord(**pMesh, tnemesh.CoordIndex, tnemesh.TexCoordIndex, ((CX3DImporter_NodeElement_TextureCoordinate*)*ch_it)->Value);
 			else
-				throw DeadlyImportError("Postprocess_BuildMesh. Unknown child of TriangleStripSet: " + std::to_string((*ch_it)->Type) + ".");
+				throw DeadlyImportError("Postprocess_BuildMesh. Unknown child of TriangleStripSet: " + to_string((*ch_it)->Type) + ".");
 		}// for(std::list<CX3DImporter_NodeElement*>::iterator ch_it = tnemesh.Child.begin(); ch_it != tnemesh.Child.end(); ch_it++)
 
 		return;// mesh is build, nothing to do anymore.
 	}// if(pNodeElement.Type == CX3DImporter_NodeElement::ENET_TriangleStripSet)
 
-	throw DeadlyImportError("Postprocess_BuildMesh. Unknown mesh type: " + std::to_string(pNodeElement.Type) + ".");
+	throw DeadlyImportError("Postprocess_BuildMesh. Unknown mesh type: " + to_string(pNodeElement.Type) + ".");
 }
 
 void X3DImporter::Postprocess_BuildNode(const CX3DImporter_NodeElement& pNodeElement, aiNode& pSceneNode, std::list<aiMesh*>& pSceneMeshList,
@@ -659,7 +660,7 @@ void X3DImporter::Postprocess_BuildNode(const CX3DImporter_NodeElement& pNodeEle
 		}
 		else if(!PostprocessHelper_ElementIsMetadata((*it)->Type))// skip metadata
 		{
-			throw DeadlyImportError("Postprocess_BuildNode. Unknown type: " + std::to_string((*it)->Type) + ".");
+			throw DeadlyImportError("Postprocess_BuildNode. Unknown type: " + to_string((*it)->Type) + ".");
 		}
 	}// for(std::list<CX3DImporter_NodeElement*>::const_iterator it = chit_begin; it != chit_end; it++)
 
diff --git a/code/glTFAsset.inl b/code/glTFAsset.inl
index 4b2f72969..fcaf4235d 100644
--- a/code/glTFAsset.inl
+++ b/code/glTFAsset.inl
@@ -1003,8 +1003,7 @@ Ref<Buffer> buf = pAsset_Root.buffers.Get(pCompression_Open3DGC.Buffer);
 	{
 		// size = number_of_elements * components_per_element * size_of_component. See float attributes note.
 		size_t tval = ifs.GetNIntAttribute(idx);
-
-		switch(ifs.GetIntAttributeType(idx))
+		switch( ifs.GetIntAttributeType( idx ) )
 		{
 			default:
 				throw DeadlyImportError("GLTF: Open3DGC. Unsupported type of int attribute: " + std::to_string(ifs.GetIntAttributeType(idx)));
diff --git a/code/glTFImporter.cpp b/code/glTFImporter.cpp
index 288cfd883..4867a9e09 100644
--- a/code/glTFImporter.cpp
+++ b/code/glTFImporter.cpp
@@ -41,8 +41,8 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #ifndef ASSIMP_BUILD_NO_GLTF_IMPORTER
 
 #include "glTFImporter.h"
-
 #include "StringComparison.h"
+#include "StringUtils.h"
 
 #include <assimp/Importer.hpp>
 #include <assimp/scene.h>
@@ -285,7 +285,7 @@ void glTFImporter::ImportMeshes(glTF::Asset& r)
 				else
 #endif
 				{
-					throw DeadlyImportError("GLTF: Can not import mesh: unknown mesh extension (code: \"" + std::to_string(cur_ext->Type) +
+					throw DeadlyImportError("GLTF: Can not import mesh: unknown mesh extension (code: \"" + to_string(cur_ext->Type) +
 											"\"), only Open3DGC is supported.");
 				}
 			}