Re: [boost] Compile Time String in C++14

TONGARI J writes:

Hi all,

I found a way to make CT strings in C++14, with the help of generic lambda.

FYI, Ábel Sinkovics has presented a c++11 CT string in his mpllibs::metaparse[1] lib before, but it requires some PP trick which has a predefined limit MPLLIBS_LIMIT_STRING_SIZE.

The new trick doesn't suffer from the limitation, but it assumes a null-terminated string. It's fairly simple, see below:

```c++ template struct str {};

template<char c> struct ch {};

template<int n> using idx = std::integral_constant;

template auto accum(S s, ch<c>, str) { return accum(s, s(idx()), str()); }

template auto accum(S, ch<0>, str ret) { return ret; }

template<class S> auto make_str(S s) { return accum(s, s(idx<0>()), str<>()); }

#define LIT(s) make_str([](auto idx) { return ch(); }) ```

Then you can use `doSomething(LIT("abc"))` in your code. What do you think?

This is genius, thanks a lot for posting. I've been searching for a way to do this to implement compile-time strings in Boost.Hana[1]. Louis [1]: https://github.com/ldionne/hana -- View this message in context: http://boost.2283326.n4.nabble.com/Compile-Time-String-in-C-14-tp4666747p466... Sent from the Boost - Dev mailing list archive at Nabble.com.