Formatters.h

#pragma once
 
#include "valkyrie/util/eigenunit/UnitMap.h"

namespace std {
template <typename... UnitTags>
struct formatter<valor::EigenUnit::UnitVector<UnitTags...>> {
    using Vec = valor::EigenUnit::UnitVector<UnitTags...>;
    valor::EigenUnit::detail::UnitFormatSpec spec;

    constexpr auto parse(format_parse_context& ctx) { return spec.parse(ctx); }

    template <typename FormatContext>
    auto format(const Vec& vec, FormatContext& ctx) const {
        auto out = ctx.out();
        *out++ = '[';
        format_impl(vec, out, std::make_index_sequence<sizeof...(UnitTags)>{});
        *out++ = ']';
        return out;
    }
 
   private:
    template <typename Out, std::size_t... Is>
    void format_impl(const Vec& vec, Out& out, std::index_sequence<Is...>) const {
        ((format_element<Is>(vec, out), (Is < sizeof...(UnitTags) - 1 ? (*out++ = ',', *out++ = ' ', void()) : void())), ...);
    }

    template <std::size_t I, typename Out>
    void format_element(const Vec& vec, Out& out) const {
        using Tag = std::tuple_element_t<I, std::tuple<UnitTags...>>;
        std::string s = spec.format_value(vec.template Get<I>().value());
        if (!spec.values_only)
            s += std::string(" ") + units::abbreviation(units::unit_t<Tag>{});
        out = std::ranges::copy(s, out).out;
    }
};

template <typename... UnitTags>
struct formatter<valor::EigenUnit::UnitMap<UnitTags...>> {
    using Map = valor::EigenUnit::UnitMap<UnitTags...>;
    valor::EigenUnit::detail::UnitFormatSpec spec;

    constexpr auto parse(format_parse_context& ctx) { return spec.parse(ctx); }

    template <typename FormatContext>
    auto format(const Map& m, FormatContext& ctx) const {
        return std::formatter<valor::EigenUnit::UnitVector<UnitTags...>>{}.format(m.ToVector(), ctx);
    }
};

template <typename... UnitTags>
struct formatter<valor::EigenUnit::ConstUnitMap<UnitTags...>> {
    using CMap = valor::EigenUnit::ConstUnitMap<UnitTags...>;
    valor::EigenUnit::detail::UnitFormatSpec spec;

    constexpr auto parse(format_parse_context& ctx) { return spec.parse(ctx); }

    template <typename FormatContext>
    auto format(const CMap& m, FormatContext& ctx) const {
        return std::formatter<valor::EigenUnit::UnitVector<UnitTags...>>{}.format(m.ToVector(), ctx);
    }
};
}  // namespace std