Создание потока boost с чистым виртуальным классом

-1

Я пытаюсь создать поток с классом обратного вызова, реализующим operator(). Класс содержит чистый виртуальный метод. Обратный вызов использует виртуальную функцию для выполнения своей обработки. Вот пример, который инкапсулирует идею и бросает некоторые ошибки компилятора:Создание потока boost с чистым виртуальным классом

#include <boost/chrono.hpp> 
#include <boost/thread.hpp> 
#include <iostream> 

class Test { 
    protected: 
     int x; 
    public: 
     Test(void): x(10) {}; 
     virtual void operator()(void); 
     boost::thread run(void); 
     virtual void a(void) = 0; 
}; 

void Test::operator()(void) { 
    this->a(); 
    x += 10; 
    std::cout << "Current Value:" << x << std::endl; 
} 

boost::thread Test::run(void) { 
    return boost::thread(*this); 
} 

class Test1 : public Test { 
    public: 
     virtual void a(void); 
}; 

void Test1::a(void) { 
    x--; 
} 

main() { 
    Test1 test = Test1(); 
    test.run().join(); 
}

Я использую GCC (GCC) 4.9.1 20140903() предварительную версию на Arch Linux. Я получаю следующие ошибки компиляции при запуске g++ test.cpp -lboost_thread -lboost_system:

test.cpp: In member function ‘boost::thread Test::run()’: 
test.cpp:22:31: error: no matching function for call to ‘boost::thread::thread(Test&)’ 
    return boost::thread(*this); 
          ^
test.cpp:22:31: note: candidates are: 
In file included from /usr/include/boost/thread/thread_only.hpp:22:0, 
       from /usr/include/boost/thread/thread.hpp:12, 
       from /usr/include/boost/thread.hpp:13, 
       from test.cpp:2: 
/usr/include/boost/thread/detail/thread.hpp:441:9: note: template<class F, class A1, class A2, class A3, class A4, class A5, class A6, class A7, class A8, class A9> boost::thread::thread(F, A1, A2, A3, A4, A5, A6, A7, A8, A9) 
     thread(F f,A1 a1,A2 a2,A3 a3,A4 a4,A5 a5,A6 a6,A7 a7,A8 a8,A9 a9): 
     ^
/usr/include/boost/thread/detail/thread.hpp:441:9: note: template argument deduction/substitution failed: 
test.cpp:22:31: note: candidate expects 10 arguments, 1 provided 
    return boost::thread(*this); 
          ^
In file included from /usr/include/boost/thread/thread_only.hpp:22:0, 
       from /usr/include/boost/thread/thread.hpp:12, 
       from /usr/include/boost/thread.hpp:13, 
       from test.cpp:2: 
/usr/include/boost/thread/detail/thread.hpp:434:9: note: template<class F, class A1, class A2, class A3, class A4, class A5, class A6, class A7, class A8> boost::thread::thread(F, A1, A2, A3, A4, A5, A6, A7, A8) 
     thread(F f,A1 a1,A2 a2,A3 a3,A4 a4,A5 a5,A6 a6,A7 a7,A8 a8): 
     ^
/usr/include/boost/thread/detail/thread.hpp:434:9: note: template argument deduction/substitution failed: 
test.cpp:22:31: note: candidate expects 9 arguments, 1 provided 
    return boost::thread(*this); 
          ^
In file included from /usr/include/boost/thread/thread_only.hpp:22:0, 
       from /usr/include/boost/thread/thread.hpp:12, 
       from /usr/include/boost/thread.hpp:13, 
       from test.cpp:2: 
/usr/include/boost/thread/detail/thread.hpp:427:9: note: template<class F, class A1, class A2, class A3, class A4, class A5, class A6, class A7> boost::thread::thread(F, A1, A2, A3, A4, A5, A6, A7) 
     thread(F f,A1 a1,A2 a2,A3 a3,A4 a4,A5 a5,A6 a6,A7 a7): 
     ^
/usr/include/boost/thread/detail/thread.hpp:427:9: note: template argument deduction/substitution failed: 
test.cpp:22:31: note: candidate expects 8 arguments, 1 provided 
    return boost::thread(*this); 
          ^
In file included from /usr/include/boost/thread/thread_only.hpp:22:0, 
       from /usr/include/boost/thread/thread.hpp:12, 
       from /usr/include/boost/thread.hpp:13, 
       from test.cpp:2: 
/usr/include/boost/thread/detail/thread.hpp:420:9: note: template<class F, class A1, class A2, class A3, class A4, class A5, class A6> boost::thread::thread(F, A1, A2, A3, A4, A5, A6) 
     thread(F f,A1 a1,A2 a2,A3 a3,A4 a4,A5 a5,A6 a6): 
     ^
/usr/include/boost/thread/detail/thread.hpp:420:9: note: template argument deduction/substitution failed: 
test.cpp:22:31: note: candidate expects 7 arguments, 1 provided 
    return boost::thread(*this); 
          ^
In file included from /usr/include/boost/thread/thread_only.hpp:22:0, 
       from /usr/include/boost/thread/thread.hpp:12, 
       from /usr/include/boost/thread.hpp:13, 
       from test.cpp:2: 
/usr/include/boost/thread/detail/thread.hpp:413:9: note: template<class F, class A1, class A2, class A3, class A4, class A5> boost::thread::thread(F, A1, A2, A3, A4, A5) 
     thread(F f,A1 a1,A2 a2,A3 a3,A4 a4,A5 a5): 
     ^
/usr/include/boost/thread/detail/thread.hpp:413:9: note: template argument deduction/substitution failed: 
test.cpp:22:31: note: candidate expects 6 arguments, 1 provided 
    return boost::thread(*this); 
          ^
In file included from /usr/include/boost/thread/thread_only.hpp:22:0, 
       from /usr/include/boost/thread/thread.hpp:12, 
       from /usr/include/boost/thread.hpp:13, 
       from test.cpp:2: 
/usr/include/boost/thread/detail/thread.hpp:406:9: note: template<class F, class A1, class A2, class A3, class A4> boost::thread::thread(F, A1, A2, A3, A4) 
     thread(F f,A1 a1,A2 a2,A3 a3,A4 a4): 
     ^
/usr/include/boost/thread/detail/thread.hpp:406:9: note: template argument deduction/substitution failed: 
test.cpp:22:31: note: candidate expects 5 arguments, 1 provided 
    return boost::thread(*this); 
          ^
In file included from /usr/include/boost/thread/thread_only.hpp:22:0, 
       from /usr/include/boost/thread/thread.hpp:12, 
       from /usr/include/boost/thread.hpp:13, 
       from test.cpp:2: 
/usr/include/boost/thread/detail/thread.hpp:399:9: note: template<class F, class A1, class A2, class A3> boost::thread::thread(F, A1, A2, A3) 
     thread(F f,A1 a1,A2 a2,A3 a3): 
     ^
/usr/include/boost/thread/detail/thread.hpp:399:9: note: template argument deduction/substitution failed: 
test.cpp:22:31: note: candidate expects 4 arguments, 1 provided 
    return boost::thread(*this); 
          ^
In file included from /usr/include/boost/thread/thread_only.hpp:22:0, 
       from /usr/include/boost/thread/thread.hpp:12, 
       from /usr/include/boost/thread.hpp:13, 
       from test.cpp:2: 
/usr/include/boost/thread/detail/thread.hpp:392:9: note: template<class F, class A1, class A2> boost::thread::thread(F, A1, A2) 
     thread(F f,A1 a1,A2 a2): 
     ^
/usr/include/boost/thread/detail/thread.hpp:392:9: note: template argument deduction/substitution failed: 
test.cpp:22:31: note: candidate expects 3 arguments, 1 provided 
    return boost::thread(*this); 
          ^
In file included from /usr/include/boost/thread/thread_only.hpp:22:0, 
       from /usr/include/boost/thread/thread.hpp:12, 
       from /usr/include/boost/thread.hpp:13, 
       from test.cpp:2: 
/usr/include/boost/thread/detail/thread.hpp:386:9: note: template<class F, class A1> boost::thread::thread(F, A1, typename boost::disable_if<boost::thread_detail::is_convertible<F&, boost::thread_attributes>, boost::thread::dummy*>::type) 
     thread(F f,A1 a1,typename disable_if<boost::thread_detail::is_convertible<F&,thread_attributes >, dummy* >::type=0): 
     ^
/usr/include/boost/thread/detail/thread.hpp:386:9: note: template argument deduction/substitution failed: 
test.cpp:22:31: note: candidate expects 3 arguments, 1 provided 
    return boost::thread(*this); 
          ^
In file included from /usr/include/boost/thread/thread_only.hpp:22:0, 
       from /usr/include/boost/thread/thread.hpp:12, 
       from /usr/include/boost/thread.hpp:13, 
       from test.cpp:2: 
/usr/include/boost/thread/detail/thread.hpp:335:9: note: boost::thread::thread(boost::detail::thread_move_t<boost::thread>) 
     thread(BOOST_THREAD_RV_REF(thread) x) BOOST_NOEXCEPT 
     ^
/usr/include/boost/thread/detail/thread.hpp:335:9: note: no known conversion for argument 1 from ‘Test’ to ‘boost::detail::thread_move_t<boost::thread>’ 
/usr/include/boost/thread/detail/thread.hpp:325:9: note: template<class F> boost::thread::thread(const attributes&, boost::detail::thread_move_t<T>) 
     thread(attributes const& attrs, BOOST_THREAD_RV_REF(F) f): 
     ^
/usr/include/boost/thread/detail/thread.hpp:325:9: note: template argument deduction/substitution failed: 
test.cpp:22:31: note: cannot convert ‘*(Test*)this’ (type ‘Test’) to type ‘const attributes& {aka const boost::thread_attributes&}’ 
    return boost::thread(*this); 
          ^
In file included from /usr/include/boost/thread/thread_only.hpp:22:0, 
       from /usr/include/boost/thread/thread.hpp:12, 
       from /usr/include/boost/thread.hpp:13, 
       from test.cpp:2: 
/usr/include/boost/thread/detail/thread.hpp:312:18: note: template<class F> boost::thread::thread(boost::detail::thread_move_t<T>, typename boost::disable_if<boost::is_same<typename boost::decay<F>::type, boost::thread>, boost::thread::dummy*>::type) 
     explicit thread(BOOST_THREAD_RV_REF(F) f 
       ^
/usr/include/boost/thread/detail/thread.hpp:312:18: note: template argument deduction/substitution failed: 
test.cpp:22:31: note: ‘Test’ is not derived from ‘boost::detail::thread_move_t<T>’ 
    return boost::thread(*this); 
          ^
In file included from /usr/include/boost/thread/thread_only.hpp:22:0, 
       from /usr/include/boost/thread/thread.hpp:12, 
       from /usr/include/boost/thread.hpp:13, 
       from test.cpp:2: 
/usr/include/boost/thread/detail/thread.hpp:303:9: note: template<class F> boost::thread::thread(const attributes&, F, typename boost::disable_if<boost::thread_detail::is_convertible<F&, boost::detail::thread_move_t<T> >, boost::thread::dummy*>::type) 
     thread(attributes const& attrs, F f 
     ^
/usr/include/boost/thread/detail/thread.hpp:303:9: note: template argument deduction/substitution failed: 
test.cpp:22:31: note: cannot convert ‘*(Test*)this’ (type ‘Test’) to type ‘const attributes& {aka const boost::thread_attributes&}’ 
    return boost::thread(*this); 
          ^
In file included from /usr/include/boost/thread/thread_only.hpp:22:0, 
       from /usr/include/boost/thread/thread.hpp:12, 
       from /usr/include/boost/thread.hpp:13, 
       from test.cpp:2: 
/usr/include/boost/thread/detail/thread.hpp:292:18: note: template<class F> boost::thread::thread(F, typename boost::disable_if_c<boost::thread_detail::is_convertible<F&, boost::detail::thread_move_t<T> >::value, boost::thread::dummy*>::type) 
     explicit thread(F f 
       ^
/usr/include/boost/thread/detail/thread.hpp:292:18: note: template argument deduction/substitution failed: 
/usr/include/boost/thread/detail/thread.hpp: In substitution of ‘template<class F> boost::thread::thread(F, typename boost::disable_if_c<boost::thread_detail::is_convertible<F&, boost::detail::thread_move_t<T> >::value, boost::thread::dummy*>::type) [with F = Test]’: 
test.cpp:22:31: required from here 
/usr/include/boost/thread/detail/thread.hpp:292:18: error: invalid abstract parameter type ‘Test’ 
test.cpp:5:7: note: because the following virtual functions are pure within ‘Test’: 
class Test { 
    ^
test.cpp:12:22: note: virtual void Test::a() 
     virtual void a(void) = 0; 
        ^
In file included from /usr/include/boost/thread/thread_only.hpp:22:0, 
       from /usr/include/boost/thread/thread.hpp:12, 
       from /usr/include/boost/thread.hpp:13, 
       from test.cpp:2: 
/usr/include/boost/thread/detail/thread.hpp:244:9: note: boost::thread::thread() 
     thread() BOOST_NOEXCEPT; 
     ^
/usr/include/boost/thread/detail/thread.hpp:244:9: note: candidate expects 0 arguments, 1 provided 
In file included from /usr/include/boost/thread/thread_only.hpp:22:0, 
       from /usr/include/boost/thread/thread.hpp:12, 
       from /usr/include/boost/thread.hpp:13, 
       from test.cpp:2: 
/usr/include/boost/thread/detail/thread.hpp:191:18: note: boost::thread::thread(boost::detail::thread_data_ptr) 
     explicit thread(detail::thread_data_ptr data); 
       ^
/usr/include/boost/thread/detail/thread.hpp:191:18: note: no known conversion for argument 1 from ‘Test’ to ‘boost::detail::thread_data_ptr {aka boost::shared_ptr<boost::detail::thread_data_base>}’ 
In file included from /usr/include/boost/thread/lock_guard.hpp:11:0, 
       from /usr/include/boost/thread/pthread/thread_data.hpp:11, 
       from /usr/include/boost/thread/thread_only.hpp:17, 
       from /usr/include/boost/thread/thread.hpp:12, 
       from /usr/include/boost/thread.hpp:13, 
       from test.cpp:2: 
/usr/include/boost/thread/detail/thread.hpp:163:7: note: boost::thread::thread(boost::thread&) 
     BOOST_THREAD_MOVABLE_ONLY(thread) 
    ^
/usr/include/boost/thread/detail/thread.hpp:163:7: note: no known conversion for argument 1 from ‘Test’ to ‘boost::thread&’

Оказывается, что существует проблема с использованием *this как функтор, когда класс имеет чисто виртуальные методы.

Что вызывает ошибку, концептуально?
Как можно реализовать функциональные возможности этого фрагмента таким образом, чтобы он компилировался?

Кстати, ожидаемый выход программы - Current Value:19.

источник

2014-11-04 Mad Physicist

Концептуально, проблема в том, что вы пытаетесь сделать Test объект - что невозможно, так как он имеет чистая виртуальная функция. Соответствующая ошибка компиляции вам похоронен где-то там:

/usr/include/boost/thread/detail/thread.hpp:292:18: note: template argument deduction/substitution failed: 
/usr/include/boost/thread/detail/thread.hpp: In substitution of ‘template<class F> boost::thread::thread(F, typename boost::disable_if_c<boost::thread_detail::is_convertible<F&, boost::detail::thread_move_t<T> >::value, boost::thread::dummy*>::type) [with F = Test]’: 
test.cpp:22:31: required from here 
/usr/include/boost/thread/detail/thread.hpp:292:18: error: invalid abstract parameter type ‘Test’ 
test.cpp:5:7: note: because the following virtual functions are pure within ‘Test’: 
class Test { 
    ^

Вы должны дать boost::thread то, что на самом деле конструктивна. Проще всего лямбда:

boost::thread Test::run(void) { 
    return boost::thread([this]{ 
     this->operator(); 
    }); 
}

[обновление] или на самом деле проще:

boost::thread Test::run(void) { 
    return boost::thread(&Test::operator(), this); 
}

источник

2014-11-04 19:49:21 Barry

Я не использую C++ 11. Я рассматриваю два варианта ATM: либо переходя в 'boost :: ref (this)', либо помещая 'operator()' во вложенную структуру и передавая это. Оба они примерно эквивалентны лямбда, хотя последнее, вероятно, предпочтительнее так как это можно сделать безопаснее. Есть предположения? –

Можете ли вы просто выполнить boost :: thread (& Test :: operator(), this) '? – Barry

LOL благодарит за изменение, что было немым. – Barry

boost::thread Конструктор требует, чтобы аргумент был пригодным для копирования, и принимает его по значению (если это не значение rvalue). Таким образом, вы хотите, чтобы компилятор создать экземпляр Test, который является абстрактным, и он не согласен:

error: invalid abstract parameter type ‘Test’

источник

2014-11-04 19:48:16

Это имеет смысл. Как это исправить? –

Создание потока boost с чистым виртуальным классом

ответ

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