+ // optimize the special common case: replacement of one character by
+ // another one (in UTF-8 case we can only do this for ASCII characters)
+ //
+ // benchmarks show that this special version is around 3 times faster
+ // (depending on the proportion of matching characters and UTF-8/wchar_t
+ // build)
+ if ( strOld.m_impl.length() == 1 && strNew.m_impl.length() == 1 )
+ {
+ const wxStringCharType chOld = strOld.m_impl[0],
+ chNew = strNew.m_impl[0];
+
+ // this loop is the simplified version of the one below
+ for ( size_t pos = 0; ; )
+ {
+ pos = m_impl.find(chOld, pos);
+ if ( pos == npos )
+ break;