meta.h

/*
 * $Id$
 * Copyright (c) 2006, IRIT-UPS.
 *
 * Meta-programming definitions.
 */
#ifndef ELM_META_H
#define ELM_META_H
 
 
namespace elm {
 
namespace meta {
 
    template <int x> struct n { enum { _ = x }; };
    struct _true { enum { _ = 1 }; };
    struct _false { enum { _ = 0 }; };
 
    template <bool c, class T, class E> struct _if: public T {  };
    template <class T, class E> struct _if<false, T, E>: public E {  };
 
    template <class> struct sfinae_true: _true { };
    template <class T> inline T& declval() { return *static_cast<T *>(nullptr); }
 
    template <typename U, typename t> struct is_same: _false { };
    template <typename U> struct is_same<U, U>: _true { };
 
    template <typename T, template <typename X> class C>
    struct is_supported {
        template <class U> static _true c(C<U> *);
        template <class U> static _false c(...);
        enum { _ = decltype(c<T>(0))::_ };
    };
 
    template<bool B, class T = void> struct enable_if {};
    template<class T> struct enable_if<true, T> { typedef T _; };
}
 
// deprecated
template <int x> struct _n { enum { _ = x }; };
struct _true { enum { _ = 1 }; };
struct _false { enum { _ = 0 }; };
template <bool c, class T, class E> struct _if: public T {  };
template <class T, class E> struct _if<false, T, E>: public E {  };
 
}   // elm
 
#endif // ELM_META_H