boost/hana/fwd/less.hpp
/*!
@file
Forward declares `boost::hana::less`.
Copyright Louis Dionne 2013-2022
Distributed under the Boost Software License, Version 1.0.
(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
*/
#ifndef BOOST_HANA_FWD_LESS_HPP
#define BOOST_HANA_FWD_LESS_HPP
#include <boost/hana/config.hpp>
#include <boost/hana/core/when.hpp>
#include <boost/hana/detail/nested_than_fwd.hpp>
namespace boost { namespace hana {
//! Returns a `Logical` representing whether `x` is less than `y`.
//! @ingroup group-Orderable
//!
//!
//! Signature
//! ---------
//! Given a Logical `Bool` and two Orderables `A` and `B` with a common
//! embedding, the signature is
//! @f$ \mathrm{less} : A \times B \to Bool @f$.
//!
//! @param x, y
//! Two objects to compare.
//!
//!
//! Example
//! -------
//! @include example/less.cpp
#ifdef BOOST_HANA_DOXYGEN_INVOKED
constexpr auto less = [](auto&& x, auto&& y) {
return tag-dispatched;
};
#else
template <typename T, typename U, typename = void>
struct less_impl : less_impl<T, U, when<true>> { };
struct less_t : detail::nested_than<less_t> {
template <typename X, typename Y>
constexpr auto operator()(X&& x, Y&& y) const;
};
BOOST_HANA_INLINE_VARIABLE constexpr less_t less{};
#endif
}} // end namespace boost::hana
#endif // !BOOST_HANA_FWD_LESS_HPP