Subject: Re: [boost] Compile Time String in C++11/C++14
From: Adam Wulkiewicz (adam.wulkiewicz_at_[hidden])
Date: 2014-08-26 07:43:17
Tongari J wrote:
> Hi Louis,
>
> 2014-08-26 0:01 GMT+08:00 Louis Dionne <ldionne.2_at_[hidden]>:
>> 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].
>>
> Glad to hear :)
>
> Actually I've found an even simpler way:
Nice! And with some small tweaks it works in C++11, assuming you have
some implementation of index_sequence:
```
template<char...>
struct str {};
template<std::size_t... Ns, class S>
auto make_str_impl(index_sequence<Ns...>, S) -> decltype(str<S::get()[Ns]...>())
{
return str<S::get()[Ns]...>();
}
template<class S>
auto make_str(S) -> decltype(make_str_impl(make_index_sequence<sizeof(S::get()) - 1>(), S()))
{
return make_str_impl(make_index_sequence<sizeof(S::get()) - 1>(), S());
}
#define LIT(s) make_str([]() \
{ \
struct \
{ \
static constexpr decltype(s) get() \
{ \
return s; \
} \
} _; \
return _; \
}())
```
Well VS2013 complains about a static data member in locally defined
class but I assume it's a VS bug.
Regards,
Adam