Re: [boost] type<>

From: Herve Bronnimann (hbr_at_[hidden])
Date: 2002-06-21 14:55:46

On Fri, Jun 21, 2002 at 10:18:50AM -0400, David Abrahams wrote:
> i-s'pose-i-could-look-at-the-sandbox-ly y'rs,

Dave is right. Here's the code:

  namespace boost {

    template <class T>
    struct identity
    {
        typedef T argument_type; // directly to avoid including <functional>
        typedef T result_type;   // directly to avoid including <functional>
        typedef T type;          // somewhat redundant with unary_function,
                                 // but apparently to satisfy mpl's interface
 
        template <class U> struct rebind { typedef identity<U> other; };
 
        // allow identity to return an lvalue if lvalue is passed as argument
        T const& operator()(T const& x) const { return x; }
        T&       operator()(T& x)       const { return x; }
    };

  }  // namespace boost

-- 
Hervé