[boost] Re: [ptr_container] metrowerks problems

From: Stefan Slapeta (stefan_at_[hidden])
Date: 2005-05-02 07:42:19

Howard Hinnant wrote:

> 
> The error message is saying that
> 
> boost::operator >= (ptr_container_detail::reversible_ptr_container< ... 
> animal...>, ...)
> 
> is being instantiated.
> 
> If I were to guess, it would be some kind of concepts check.  
> ptr_container_detail::reversible_ptr_container does derive from 
> less_than_comparable.
> 

[...]

Actually, it's instantiated here:

bool operator<( const reversible_ptr_container& r ) const // nothrow
{
    return std::lexicographical_compare( begin(), end(), r.begin(), 
r.end() );
}

which again is instantiated here:

template <class T, class B = ::boost::detail::empty_base>
struct less_than_comparable1 : B
{
   friend bool operator>(const T& x, const T& y)  { return y < x; }
   friend bool operator<=(const T& x, const T& y) { return !(y < x); }
   friend bool operator>=(const T& x, const T& y) { return !(x < y); }
};

Stefan