Result.h

#pragma once

#include <cstdint>

namespace fsdk
{

    template<typename E>
    struct ErrorTraits
    {
        static bool isOk(E) noexcept {
            return false;
        }

        static const char* toString (E) noexcept {
            return "NOT AVAILABLE";
        }
    };

    template<typename E>
    struct Result
    {
        using ErrorType = E;
        using Traits = ErrorTraits<E>;

        explicit Result(E error) noexcept
            : m_error(error) {}
        
        Result() noexcept
            : m_error(E::Ok) {}

        E getError() const noexcept {
            return m_error;
        }

        bool isError() const noexcept {
            return !isOk();
        }

        bool isOk() const noexcept {
            return Traits::isOk(m_error);
        }

        operator bool () const noexcept {
            return isOk();
        }

        const char* what() const noexcept {
            return Traits::toString(getError());
        }

    private:
        E m_error;  
    };

    template<typename E>
    inline Result<E> makeResult(E error) noexcept {
        return Result<E>(error);
    }
}