Extract and reuse conversion code
diff --git a/tinyxml2.cpp b/tinyxml2.cpp
index 5cdedbb..a8a4a20 100755
--- a/tinyxml2.cpp
+++ b/tinyxml2.cpp
@@ -2380,8 +2380,9 @@
     }

     for( int i=0; i<NUM_ENTITIES; ++i ) {

         const char entityValue = entities[i].value;

-        TIXMLASSERT( ((unsigned char)entityValue) < ENTITY_RANGE );

-        _entityFlag[ (unsigned char)entityValue ] = true;

+        const unsigned char flagIndex = (unsigned char)entityValue;

+        TIXMLASSERT( flagIndex < ENTITY_RANGE );

+        _entityFlag[flagIndex] = true;

     }

     _restrictedEntityFlag[(unsigned char)'&'] = true;

     _restrictedEntityFlag[(unsigned char)'<'] = true;