[libcxx-commits] [PATCH] D112017: [libcxx][format] Fix how we handle char traits in formatter<string> and formatter<string_view>

[Victor Zverovich via Phabricator via libcxx-commits]

vitaut added inline comments.


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Comment at: libcxx/include/__format/formatter.h:184-186
+template <class _CharT, class _Traits, class _Fill>
+_LIBCPP_HIDE_FROM_ABI auto __write_unicode(output_iterator<const _CharT&> auto __out_it,
+                                           basic_string_view<_CharT, _Traits> __str, ptrdiff_t __width,
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DanielMcIntosh-IBM wrote:
> vitaut wrote:
> > I don't think traits are needed in this internal function. It might be better to convert `basic_string_view<_CharT, _Traits>` into `basic_string_view<_CharT>` when calling it and remove `_Traits` here to prevent template bloat.
> If my understanding of templates is correct, when `_Traits != char_traits<_CharT>`, then `basic_string_view<_CharT, _Traits>` is a totally different type from `basic_string_view<_CharT> == basic_string_view<_CharT, char_traits<_CharT>>`, and may not be convertible to `basic_string_view<_CharT>`.
Yes but string view is just a pointer and a size so you can do `basic_string_view<_CharT>(__str.data(), __str.size())` at the `__write_unicode` call site.


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  https://reviews.llvm.org/D112017/new/

https://reviews.llvm.org/D112017