fiber/src/future.cpp

//          Copyright Oliver Kowalke 2013.
// Distributed under the Boost Software License, Version 1.0.
//    (See accompanying file LICENSE_1_0.txt or copy at
//          http://www.boost.org/LICENSE_1_0.txt)

#include "boost/fiber/exceptions.hpp"

namespace boost {
namespace fibers {

class future_error_category : public std::error_category {
public:
    virtual const char* name() const noexcept {
        return "fiber-future";
    }

    virtual std::error_condition default_error_condition( int ev) const noexcept {
        switch ( static_cast< future_errc >( ev) ) {
            case future_errc::broken_promise:
                return std::error_condition{
                        static_cast< int >( future_errc::broken_promise),
                        future_category() };
            case future_errc::future_already_retrieved:
                return std::error_condition{
                        static_cast< int >( future_errc::future_already_retrieved),
                        future_category() };
            case future_errc::promise_already_satisfied:
                return std::error_condition{
                        static_cast< int >( future_errc::promise_already_satisfied),
                        future_category() };
            case future_errc::no_state:
                return std::error_condition{
                        static_cast<
                        int >( future_errc::no_state),
                        future_category() };
            default:
                return std::error_condition{ ev, * this };
        }
    }

    virtual bool equivalent( std::error_code const& code, int condition) const noexcept {
        return * this == code.category() &&
            static_cast< int >( default_error_condition( code.value() ).value() ) == condition;
    }

    virtual std::string message( int ev) const {
        switch ( static_cast< future_errc >( ev) ) {
            case future_errc::broken_promise:
                return std::string{ "The associated promise has been destructed prior "
                        "to the associated state becoming ready." };
            case future_errc::future_already_retrieved:
                return std::string{ "The future has already been retrieved from "
                        "the promise or packaged_task." };
            case future_errc::promise_already_satisfied:
                return std::string{ "The state of the promise has already been set." };
            case future_errc::no_state:
                return std::string{ "Operation not permitted on an object without "
                        "an associated state." };
        }
        return std::string{ "unspecified future_errc value\n" };
    }
};

BOOST_FIBERS_DECL
std::error_category const& future_category() noexcept {
    static fibers::future_error_category cat;
    return cat;
}

}}