constant.hpp

Go to the documentation of this file.

// Copyright (C) 2020-2023 Jonathan Müller and lexy contributors
// SPDX-License-Identifier: BSL-1.0
 
#ifndef LEXY_CALLBACK_CONSTANT_HPP_INCLUDED
#define LEXY_CALLBACK_CONSTANT_HPP_INCLUDED
 
#include <lexy/callback/base.hpp>
 
namespace lexy
{
template <typename T>
struct _constant
{
    T _value;
 
    using return_type = T;
 
    constexpr const T& operator()() const
    {
        return _value;
    }
};
 
template <typename Arg>
LEXY_CONSTEVAL auto constant(Arg&& value)
{
    return _constant<std::decay_t<Arg>>{LEXY_FWD(value)};
}
} // namespace lexy
 
#endif // LEXY_CALLBACK_CONSTANT_HPP_INCLUDED