Re: [boost] [Better Enums] More complete release - feedbackrequested

Subject: Re: [boost] [Better Enums] More complete release - feedbackrequested
From: Peter Dimov (lists_at_[hidden])
Date: 2015-06-12 10:30:14

Anton Bachin wrote:
> On Jun 12, 2015, at 05:51, Peter Dimov <lists_at_[hidden]> wrote:
>
> > Streams are already templated, so artificial templating shouldn't be 
> > necessary if you use basic_istream and basic_ostream.
>
> But the compiler is able to instantiate those eagerly if a type argument 
> is specified (char) that does not depend on the outer template parameter.

It is. What I meant was:

template <class Ch, class Tr, class Enum>
inline std::basic_ostream<Ch, Tr>&
operator <<(std::basic_ostream<Ch, Tr>& os, const Enum& value)
{
    return os << value.template _to_basic_string<Ch>();
}

You'll have to define _to_basic_string for char, wchar_t, char16_t and 
char32_t if you want to cover all cases, of course.

If you want to restrict yourself to char-based streams:

template <class Tr, class Enum>
inline std::basic_ostream<char, Tr>&
operator <<(std::basic_ostream<char, Tr>& os, const Enum& value)
{
    return os << value._to_string();
}

although it's better to handle at least wchar_t as well.