it would be nice if bp::detail::text::utf_iterator did nothing if FromFormat==ToFormat

[andreasbuhr]

Because I know that boost.parser uses utf32 internally, I specify all string literals as utf32 strings, like bp::lit(U"keyword").

Now I see in the profiler that quite some time is spent in utf_iterator<4,4,...>::read().
If FromFormat and ToFormat are identical, no transcoding is necessary. It would be nice if utf_iterator skipped all internal recoding if FromFormat and ToFormat are identical. Everything can be forwarded to curr().

[tzlaine]

This is a reasonable complaint, but I'm not going to address it now. I'm waiting for P2728 to get farther along, and use that design -- which will eventually obviate this issue.