parcel.hpp

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#pragma once
 
 
#if !defined(TAGVAL_WITH_PARCEL)
#if __has_include(<parcel/parcel.h>)
#define TAGVAL_WITH_PARCEL 1
#else
#define TAGVAL_WITH_PARCEL 0
#endif
#endif
 
#if TAGVAL_WITH_PARCEL
 
#include <tagval/base.hpp>
#include <tagval/json_nlohmann.hpp>
 
#include <concepts>
#include <memory>
#include <string>
#include <string_view>
 
#include <parcel/parcel.h>
 
namespace tagval {
 
template <typename TagT>
    requires std::derived_from<TagT, detail::TagValBaseTag>
class TagValCell : public ::parcel::BaseCell<TagValCell<TagT>, TagT> {
    using base_t = ::parcel::BaseCell<TagValCell<TagT>, TagT>;
 
public:
    using base_t::base_t;
    using base_t::operator=;
 
    static constexpr std::string_view kind_id = "tagval";
 
    [[nodiscard]] std::string to_string() const override {
        return std::string{this->value.code()};
    }
 
    static ::parcel::cell_t from_json(::parcel::json_t const& j, ::parcel::ParcelRegistry const&) {
        auto v = base_t::template cell_from_json<TagT>(j, kind_id);
        auto cell = std::make_shared<TagValCell>(v);
        base_t::absorb_display_info(j, cell);
        return cell;
    }
 
    static ::parcel::cell_type_descriptor_t descriptor() {
        // The parcel descriptor is per-type and process-wide static (shared
        // across every value of TagT), so per-value icon/color cannot live
        // here — those stay reachable via the handle (e.g. cell.value.icon()).
        // Source the type-level name plus the kind-level (per-type) icon/color
        // from TagT::descriptor().
        static const auto d = [] {
            constexpr auto kd = TagT::descriptor();  // per-type TagValDescriptor
            ::parcel::DisplayInfo info{};
            info.name = "tagval::TagVal";
            if (kd.icon) {
                info.icon = *kd.icon;
            }
            if (kd.color) {
                info.color = *kd.color;
            }
            return std::make_shared<::parcel::SimpleCellTypeDescriptor<TagValCell>>(info);
        }();
        return d;
    }
};
 
}  // namespace tagval
 
#endif  // TAGVAL_WITH_PARCEL