iso_15924.hpp

// Copyright Take Vos 2021-2022.
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at https://www.boost.org/LICENSE_1_0.txt)
 
#pragma once
 
#include "../exception.hpp"
#include "../unicode/unicode_script.hpp"
#include "../unicode/unicode_bidi_class.hpp"
#include <string_view>
#include <cstdint>
#include <format>
 
namespace hi::inline v1 {
 
class iso_15924 {
public:
    constexpr iso_15924() noexcept : _v(999) {}
    constexpr iso_15924(iso_15924 const &) noexcept = default;
    constexpr iso_15924(iso_15924 &&) noexcept = default;
    constexpr iso_15924 &operator=(iso_15924 const &) noexcept = default;
    constexpr iso_15924 &operator=(iso_15924 &&) noexcept = default;
 
    constexpr iso_15924(uint16_t number) : _v(number) {
        if (number > 999) {
            throw parse_error(std::format("Invalid script number '{}'", number));
        }
    }
 
    iso_15924(unicode_script const &script) noexcept;
    iso_15924(std::string_view code4);
 
    [[nodiscard]] constexpr bool empty() const noexcept
    {
        return _v == 999;
    }
 
    explicit operator bool() const noexcept
    {
        return not empty();
    }
 
    [[nodiscard]] constexpr uint16_t number() const noexcept {
        return _v;
    }
 
    [[nodiscard]] std::string_view code4() const noexcept;
 
    [[nodiscard]] std::string_view code4_open_type() const noexcept;
 
    [[nodiscard]] unicode_bidi_class writing_direction() const noexcept;
 
    [[nodiscard]] constexpr friend bool operator==(iso_15924 const &lhs, iso_15924 const &rhs) noexcept = default;
 
private:
    uint16_t _v;
};
 
} // namespace hi::inline v1
 
template<>
struct std::hash<hi::iso_15924> {
    [[nodiscard]] size_t operator()(hi::iso_15924 const &rhs) const noexcept
    {
        return std::hash<uint16_t>{}(rhs.number());
    }
};