Sprout/sprout/functional/bind1st.hpp
2012-04-11 23:28:29 +09:00

34 lines
1,009 B
C++

#ifndef SPROUT_FUNCTIONAL_BIND1ST_HPP
#define SPROUT_FUNCTIONAL_BIND1ST_HPP
#include <sprout/config.hpp>
#include <sprout/functional/base.hpp>
namespace sprout {
// Copyright (C) 2011 RiSK (sscrisk)
// D.9.1 Class template binder1st
template<typename Fn>
class binder1st
: public sprout::unary_function<typename Fn::second_argument_type, typename Fn::result_type>
{
protected:
Fn op;
typename Fn::first_argument_type value;
public:
SPROUT_CONSTEXPR binder1st(Fn const& x, typename Fn::first_argument_type const& y)
: op(x), value(y)
{}
SPROUT_CONSTEXPR typename Fn::result_type operator()(typename Fn::second_argument_type const& x) const {
return op(value, x);
}
};
// D.9.2 bind1st
template<typename Fn, typename T>
SPROUT_CONSTEXPR sprout::binder1st<Fn> bind1st(Fn const& fn, T const& x) {
return sprout::binder1st<Fn>(fn, typename Fn::first_argument_type(x));
}
} // namespace sprout
#endif // #ifndef SPROUT_FUNCTIONAL_BIND1ST_HPP