libcruft-util/cruft/util/coord/iostream.hpp

/*
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * Copyright 2016-2019 Danny Robson <danny@nerdcruft.net>
 */

#pragma once

#include <cruft/util/coord/traits.hpp>
#include <cruft/util/iterator/infix.hpp>

#include <fmt/format.h>
#include <fmt/ranges.h>

#include <cstddef>
#include <ostream>
#include <algorithm>


namespace cruft {
    template <
        typename K,
        typename = std::enable_if_t<is_coord_v<K>,void>
    >
    std::ostream&
    operator<< (std::ostream &os, const K &k)
    {
        os << "[";
        std::transform (std::cbegin (k),
                        std::cend   (k),
                        iterator::infix_iterator<typename K::value_type> (os, ", "),
                        [] (auto i) { return +i; });
        os << "]";

        return os;
    }
}


template <typename T, typename Char>
requires (cruft::is_coord_v<T>)
struct fmt::range_format_kind<T, Char> :
    std::integral_constant<fmt::range_format, fmt::range_format::disabled> {};


template <typename T, typename Char>
requires (cruft::is_coord_v<std::remove_cvref_t<T>>)
struct fmt::formatter<T, Char> {
    constexpr auto
    parse (format_parse_context &ctx)
    {
        return ctx.begin ();
    }

    auto
    format (T const &val, format_context &ctx) const
    {
        return fmt::format_to (
            ctx.out (),
            "[{}]",
            fmt::join (std::begin (val), std::end (val), ", ")
        );
    }
};