Re: [boost] Static constexpr map

On 1/15/2016 7:00 PM, Nevin Liber wrote:

On 14 January 2016 at 22:41, Marshall Clow wrote:

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On Wed, Jan 13, 2016 at 11:43 AM, Niall Douglas

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wrote:

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Sadly, the current proposal for string_view does not provide a default Traits length function which is constexpr for const char *. Yes, I find that very daft as a default design choice for a string_view, but the macro at least makes it not too irritating.

It uses the existing char_traits classes, which, as you note, are not constexpr. (for some *very odd* reasons).

But writing your own traits class that has constexpr len/compare/etc is really, really simple. Maybe I'll do that this weekend, and add it to boost. :-)

Because it gets passed in as a template parameter, it isn't really all that general a solution, as it makes your string and string_view types different than std::string and std::experimental_string_view.

This is a very good point. However, nothing stops us from internally mapping `std::char_traits<CharT>` to `boost::detail::constexpr_char_traits<CharT>` when the compiler supports C++14 constexpr. Regards, -- Agustín K-ballo Bergé.- http://talesofcpp.fusionfenix.com