worldspawn/libs/signal/isignal.h

#if !defined( INCLUDED_ISIGNAL_H )
#define INCLUDED_ISIGNAL_H

#include "generic/callback.h"
#include "signal/signalfwd.h"

class SignalHandlerResult
{
bool value;
public:
explicit SignalHandlerResult( bool value ) : value( value ){
}
bool operator==( SignalHandlerResult other ) const {
	return value == other.value;
}
bool operator!=( SignalHandlerResult other ) const {
	return !operator==( other );
}
};

const SignalHandlerResult SIGNAL_CONTINUE_EMISSION = SignalHandlerResult( false );
const SignalHandlerResult SIGNAL_STOP_EMISSION = SignalHandlerResult( true );

template<class Caller, class F>
class SignalHandlerCallerN;

template<class Caller, class R, class... Ts>
class SignalHandlerCallerN<Caller, R(Ts...)> {
public:
    using func = SignalHandlerResult(Ts...);

    static SignalHandlerResult call(Ts... args) {
        Caller::call(args...);
        return SIGNAL_CONTINUE_EMISSION;
    }
};

template<class Caller>
using SignalHandlerCaller = SignalHandlerCallerN<Caller, get_func<Caller>>;

template<class Caller>
using SignalHandlerCaller1 = SignalHandlerCaller<Caller>;

template<class Caller>
using SignalHandlerCaller2 = SignalHandlerCaller<Caller>;

template<typename Caller>
using SignalHandlerCaller3 = SignalHandlerCaller<Caller>;

template<typename Caller>
using SignalHandlerCaller4 = SignalHandlerCaller<Caller>;

template<typename Other, typename True, typename False, typename Type>
class TypeEqual {
public:
    using type = False;
};

template<typename Other, typename True, typename False>
class TypeEqual<Other, True, False, Other> {
public:
    using type = True;
};

template<class CB, template<class T> class Wrapper>
class SignalHandlerN : public CB {
public:
    template<typename Caller>
    SignalHandlerN(const BindFirstOpaque<Caller> &caller)
            : CB(BindFirstOpaque<typename TypeEqual<
            SignalHandlerResult,
            Caller,
            Wrapper<Caller>,
            get_result_type<Caller>
    >::type>(caller.getBound())) {
    }
};

class SignalHandler : public SignalHandlerN<Callback<SignalHandlerResult()>, SignalHandlerCaller1> {
    using SignalHandlerN<Callback<SignalHandlerResult()>, SignalHandlerCaller1>::SignalHandlerN;
};

template<typename Caller>
inline SignalHandler makeSignalHandler( const BindFirstOpaque<Caller>& caller ){
	return SignalHandler( caller );
}
template<typename Caller>
inline SignalHandler makeSignalHandler(const Caller &caller, get_argument<Caller, 0> callee) {
	return SignalHandler( BindFirstOpaque<Caller>( callee ) );
}

template<typename FirstArgument>
class SignalHandler1 : public SignalHandlerN<Callback<SignalHandlerResult(FirstArgument)>, SignalHandlerCaller2> {
    using SignalHandlerN<Callback<SignalHandlerResult(FirstArgument)>, SignalHandlerCaller2>::SignalHandlerN;
};

template<typename Caller>
inline SignalHandler1<get_argument<Caller, 1>> makeSignalHandler1(const BindFirstOpaque<Caller> &caller) {
    return SignalHandler1<get_argument<Caller, 1>>(caller);
}
template<typename Caller>
inline SignalHandler1<get_argument<Caller, 1>>
makeSignalHandler1(const Caller &caller, get_argument<Caller, 0> callee) {
    return SignalHandler1<get_argument<Caller, 1>>(BindFirstOpaque<Caller>(callee));
}

template<typename FirstArgument, typename SecondArgument>
class SignalHandler2
        : public SignalHandlerN<Callback<SignalHandlerResult(FirstArgument, SecondArgument)>, SignalHandlerCaller3> {
    using SignalHandlerN<Callback<SignalHandlerResult(FirstArgument, SecondArgument)>, SignalHandlerCaller3>::SignalHandlerN;
};

template<typename Caller>
inline SignalHandler2<
        get_argument<Caller, 1>,
        get_argument<Caller, 2>
> makeSignalHandler2(const BindFirstOpaque<Caller> &caller) {
	return SignalHandler2<
            get_argument<Caller, 1>,
            get_argument<Caller, 2>
			   >( caller );
}
template<typename Caller>
inline SignalHandler2<
        get_argument<Caller, 1>,
        get_argument<Caller, 2>
> makeSignalHandler2(const Caller &caller, get_argument<Caller, 0> callee) {
	return SignalHandler2<
            get_argument<Caller, 1>,
            get_argument<Caller, 2>
    >(BindFirstOpaque<Caller>(callee));
}

template<typename FirstArgument, typename SecondArgument, typename ThirdArgument>
class SignalHandler3
        : public SignalHandlerN<Callback<SignalHandlerResult(FirstArgument, SecondArgument, ThirdArgument)>, SignalHandlerCaller4> {
    using SignalHandlerN<Callback<SignalHandlerResult(FirstArgument, SecondArgument, ThirdArgument)>, SignalHandlerCaller4>::SignalHandlerN;
};

template<typename Caller>
inline SignalHandler3<
        get_argument<Caller, 1>,
        get_argument<Caller, 2>,
        get_argument<Caller, 3>
> makeSignalHandler3(const BindFirstOpaque<Caller> &caller) {
	return SignalHandler3<
            get_argument<Caller, 1>,
            get_argument<Caller, 2>,
            get_argument<Caller, 3>
			   >( caller );
}
template<typename Caller>
inline SignalHandler3<
        get_argument<Caller, 1>,
        get_argument<Caller, 2>,
        get_argument<Caller, 3>
> makeSignalHandler3(const Caller &caller, get_argument<Caller, 0> callee) {
	return SignalHandler3<
            get_argument<Caller, 1>,
            get_argument<Caller, 2>,
            get_argument<Caller, 3>
    >(BindFirstOpaque<Caller>(callee));
}

#endif