Re: [Boost-users] partial specialization: mpl?

From: David Abrahams (dave_at_[hidden])
Date: 2005-07-14 20:24:53

Cory Nelson <phrosty_at_[hidden]> writes:

> I have a function like:
>
> template<typename CharT>
> void foo() {
>    std::basic_string<CharT> str;
>
>    ...
>
>    if(str=="bar")
>
>   ...
> }
>
> I'd like to check at compile time if CharT is a char or wchar_t to
> specialize the string used to compare- MPL seems like the thing I
> would use for this but documentation on doing this seems scarce. 

Probably because MPL is a slightly overpowerful tool for the job.

> Could someone give me an example?

  template <class CharT>
  charT const* bar() { return "bar"; }

  template <>
  wchar_t const* bar() { return L"bar"; }

  ...

     if (str==bar<CharT>())
       ...

HTH,

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com