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pilotclient/src/blackmisc/invoke.h

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/* Copyright (C) 2015
* swift Project Community / Contributors
*
* This file is part of swift project. It is subject to the license terms in the LICENSE file found in the top-level
* directory of this distribution and at http://www.swift-project.org/license.html. No part of swift project,
* including this file, may be copied, modified, propagated, or distributed except according to the terms
* contained in the LICENSE file.
*/
//! \file
#ifndef BLACKMISC_INVOKE_H
#define BLACKMISC_INVOKE_H
#include <tuple>
#include "blackmisc/typetraits.h"
#include "blackmisc/integersequence.h"
namespace BlackMisc
{
//! \cond PRIVATE
namespace Private
{
// Our own version of C++17 std::invoke().
template <typename F, typename T, typename = std::enable_if_t<std::is_member_object_pointer<F>::value>>
decltype(auto) invoke(F ptr, T &&object)
{
return std::forward<T>(object).*ptr;
}
template <typename F, typename T, typename... Ts, typename = std::enable_if_t<std::is_member_function_pointer<F>::value>>
decltype(auto) invoke(F ptr, T &&object, Ts &&... args)
{
return (std::forward<T>(object).*ptr)(std::forward<Ts>(args)...);
}
template <typename F, typename... Ts, typename = std::enable_if_t<! std::is_member_pointer<std::decay_t<F>>::value>>
decltype(auto) invoke(F &&func, Ts &&... args)
{
return std::forward<F>(func)(std::forward<Ts>(args)...);
}
// Like invoke() but ignores the first argument if callable is not a member function. For uniform calling of callables with slot semantics.
template <typename F, typename T, typename U, size_t... Is>
decltype(auto) invokeSlotImpl(F ptr, T *object, U tuple, std::index_sequence<Is...>, std::true_type)
{
Q_UNUSED(tuple); // in case the pack expansion is empty
return (object->*ptr)(std::forward<std::tuple_element_t<Is, U>>(std::get<Is>(tuple))...);
}
template <typename F, typename T, typename U, size_t... Is>
decltype(auto) invokeSlotImpl(F &&func, T *, U tuple, std::index_sequence<Is...>, std::false_type)
{
Q_UNUSED(tuple); // in case the pack expansion is empty
return std::forward<F>(func)(std::forward<std::tuple_element_t<Is, U>>(std::get<Is>(tuple))...);
}
template <typename F, typename T, typename... Ts>
decltype(auto) invokeSlot(F &&func, T *object, Ts &&... args)
{
using seq = MaskSequence<std::make_index_sequence<sizeof...(Ts)>, ! TIsQPrivateSignal<std::decay_t<Ts>>::value...>;
return invokeSlotImpl(std::forward<F>(func), object, std::forward_as_tuple(std::forward<Ts>(args)...), seq(), std::is_member_pointer<std::decay_t<F>>());
}
}
//! \endcond
}
#endif