Replace NULL by nullptr

src/OpenMesh/Core/IO/OMFormat.cc

@@ -135,7 +135,7 @@ namespace OMFormat {
       default:
 	std::clog << "as_string(Chunk::Entity): Invalid value!";
     }
-    return NULL;
+    return nullptr;
   }
 
 
@@ -153,7 +153,7 @@ namespace OMFormat {
       case Chunk::Type_Custom:   return "Custom";
       case Chunk::Type_Topology: return "Topology";
     }
-    return NULL;
+    return nullptr;
   }
 
 
@@ -172,7 +172,7 @@ namespace OMFormat {
       case Chunk::Dim_7D: return "7D";
       case Chunk::Dim_8D: return "8D";
     }
-    return NULL;
+    return nullptr;
   }
 
 
@@ -187,7 +187,7 @@ namespace OMFormat {
       case Chunk::Integer_32 : return "32";
       case Chunk::Integer_64 : return "64";
     }
-    return NULL;
+    return nullptr;
   }
 
   const char *as_string(Chunk::Float_Size d)
@@ -198,7 +198,7 @@ namespace OMFormat {
       case Chunk::Float_64 : return "64";
       case Chunk::Float_128: return "128";
     }
-    return NULL;
+    return nullptr;
   }