CompoundFileReader: fix UTF16~wstring conversion on 16b wchar compilers

thirdparty/compoundfilereader/utf.h

@@ -102,25 +102,32 @@ template <typename T>
 std::wstring UTF16ToWstring(const T* u16, size_t len = 0)
 {
     std::wstring ret;
-#ifdef _MSC_VER
-    while (*u16) ret += *u16++;
-#else
+    if( sizeof( wchar_t ) == 2 )
+    {
+        while( *u16 )
+            ret += *u16++;
+    }
+    else
+    {
         uint32_t cp;
         size_t   pos = 0;
         while( GetNextCodePointFromUTF16( u16, len, &pos, &cp ) )
         {
             ret += cp;
         }
-#endif
+    }
     return ret;
 }
 
 template <typename T>
 std::string WstringToUTF8(const T* wstr)
 {
-#ifdef _MSC_VER
+    if( sizeof( wchar_t ) == 2 )
+    {
         return UTF16ToUTF8( wstr );
-#else
+    }
+    else
+    {
         std::string u8;
         uint32_t    cp;
         while( ( cp = *wstr++ ) != 0 )
@@ -132,6 +139,7 @@ std::string WstringToUTF8(const T* wstr)
                 u8 += static_cast<char>( c[i] );
             }
         }
+    }
     return u8;
 #endif
 }