c++ - C++11 run templated class function with std::thread -


cannot pass function argument std::thread when class defined template.

compiler: gcc 4.8.2 language: c++11

code:

//---------test.h----------------------- #ifndef test_h #define test_h #include <iostream> #include <thread> using namespace std;  template <class t> class test { public:     test();      void thr(t n);     void testthread();  };  #endif // test_h  //---------test.cpp----------------------- #include "test.h"  template <class t> test<t>::test() { }  template <class t> void test<t>::thr(t n) {         cout << n << endl; }  template <class t> void test<t>::testthread() {     t n = 8;      thread t(thr, n);     t.join(); }  //---------main.cpp-----------------------  #include <iostream> using namespace std;  #include "test.h" #include "test.cpp"  int main() {     test<double> tt;     tt.testthread();     return 0; }

compiler error:

    in file included ../std_threads/main.cpp:5:0: ../std_threads/test.cpp: in instantiation of 'void test<t>::testthread() [with t = double]': ../std_threads/main.cpp:10:19:   required here ../std_threads/test.cpp:19:20: error: no matching function call 'std::thread::thread(<unresolved overloaded function type>, double&)'      thread t(thr, n);                     ^ ../std_threads/test.cpp:19:20: note: candidates are: in file included ../std_threads/test.h:4:0,                  ../std_threads/main.cpp:4: /usr/include/c++/4.8.2/thread:133:7: note: std::thread::thread(_callable&&, _args&& ...) [with _callable = void (test<double>::*)(double); _args = {double&}]        thread(_callable&& __f, _args&&... __args)        ^ /usr/include/c++/4.8.2/thread:133:7: note:   no known conversion argument 1 '<unresolved overloaded function type>' 'void (test<double>::*&&)(double)' /usr/include/c++/4.8.2/thread:128:5: note: std::thread::thread(std::thread&&)      thread(thread&& __t) noexcept      ^ /usr/include/c++/4.8.2/thread:128:5: note:   candidate expects 1 argument, 2 provided /usr/include/c++/4.8.2/thread:122:5: note: std::thread::thread()      thread() noexcept = default;      ^ /usr/include/c++/4.8.2/thread:122:5: note:   candidate expects 0 arguments, 2 provided make: *** [main.o] error 1 20:48:35: process "/usr/bin/make" exited code 2. error while building/deploying project std_threads (kit: desktop) when executing step 'make'

you need specify member function name , pass argument implicit first parameter of non-static member function:

thread t(&test<t>::thr, this, n);

see std::thread of member function.


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