match.hxx

Go to the documentation of this file.

// -*- C++ -*- Header compatibility <match.hxx>
 
 
#ifndef CORTEX_MATCH
#define CORTEX_MATCH
 
#include <utility>
#include <variant>
 
#if __cpp_concepts >= 201907L
#    include <concepts>
#endif  //< __cpp_concepts >= 201907L
 
namespace cxl::utils
{
 
    template<typename... Fs>
    struct match : Fs...
    {
 
        template<class... Ts>
        explicit match(Ts&&... ts)
            : Fs { std::forward<Ts>(ts) }... { }
 
        using Fs::operator()...;
    
    };  //< class match
 
    template<typename... Fs>
    match(Fs&&...) -> match<std::remove_reference_t<Fs>...>;
 
    template<typename... Ts, typename... Fs>
    constexpr auto
    operator>> (
        const std::variant<Ts...>& var,
        const match<Fs...>& m
    ) -> void
    { std::visit(m, var); }
 
    template<typename... Ts, typename... Fs>
    constexpr auto
    operator<< (
        const std::variant<Ts...>& var,
        const match<Fs...>& m
    ) -> decltype(auto) 
    { return std::visit(m, var); }
 
    struct match_any
    {
        template<typename T>
        explicit constexpr match_any([[maybe_unused]] T&& t) noexcept { }
 
        explicit constexpr match_any(const match_any&) noexcept = delete;
        explicit constexpr match_any(match_any&&) noexcept      = delete;
 
        constexpr auto
        operator= (const match_any&) noexcept -> match_any& = delete;
 
        constexpr auto
        operator= (match_any&&) noexcept -> match_any& = delete;
 
        constexpr ~match_any() noexcept = delete;
    };
 
}  //< namespace cxl::utils
 
#endif  //< CORTEX_MATCH