multithreading - C++ Passing a reference variable to the thread in g++-4.7.4 -

i need start thread passing complex parameters (std::thread<>) parameter when thread starts. i´m using `std::ref. code works fine updated environments (g++-4.8.2 running on ubuntu).

now have compile same code in old compiler (g++4.7.4) , i´m getting errors.

the code shown below, error:

readerthread.hpp

class readerthread {     void start(reader reader, synccontroller &synccontroller); } 

readerthread.cpp

void readerthread::start(reader reader, synccontroller &synccontroller) {          something... } 

main.cpp

int main() {      ...do stuff...      /*       * create , start reader thread. created object must live      * during whole thread life.      * std::ref used pass reference      */     myreader = readerfactory(params);      std::shared_ptr<readerthread> ptr(new readerthread);      std::thread th(&readerthread::start, ptr, myreader, std::ref(synccontroller));       ...do other stuff... } 

error:

in file included /usr/gcc-4.7.4/lib/gcc/i586-pc-linux-gnu/4.7.4/../../../../include/c++/4.7.4/bits/move.h:57:0,                  /usr/gcc-4.7.4/lib/gcc/i586-pc-linux-gnu/4.7.4/../../../../include/c++/4.7.4/bits/stl_pair.h:61,                  /usr/gcc-4.7.4/lib/gcc/i586-pc-linux-gnu/4.7.4/../../../../include/c++/4.7.4/bits/stl_algobase.h:65,                  /usr/gcc-4.7.4/lib/gcc/i586-pc-linux-gnu/4.7.4/../../../../include/c++/4.7.4/bits/char_traits.h:41,                  /usr/gcc-4.7.4/lib/gcc/i586-pc-linux-gnu/4.7.4/../../../../include/c++/4.7.4/ios:41,                  /usr/gcc-4.7.4/lib/gcc/i586-pc-linux-gnu/4.7.4/../../../../include/c++/4.7.4/ostream:40,                  /usr/gcc-4.7.4/lib/gcc/i586-pc-linux-gnu/4.7.4/../../../../include/c++/4.7.4/iostream:40,                  ./main.cpp:11: /usr/gcc-4.7.4/lib/gcc/i586-pc-linux-gnu/4.7.4/../../../../include/c++/4.7.4/type_traits: in instantiation of 'struct std::_result_of_impl<false, false, std::_mem_fn<void (readerthread::*)(reader, synccontroller&)>, std::shared_ptr<readerthread>, reader, std::reference_wrapper<synccontroller> >': /usr/gcc-4.7.4/lib/gcc/i586-pc-linux-gnu/4.7.4/../../../../include/c++/4.7.4/type_traits:1857:12:   required 'class std::result_of<std::_mem_fn<void (readerthread::*)(reader, synccontroller&)>(std::shared_ptr<readerthread>, reader, std::reference_wrapper<synccontroller>)>' /usr/gcc-4.7.4/lib/gcc/i586-pc-linux-gnu/4.7.4/../../../../include/c++/4.7.4/functional:1563:61:   required 'struct std::_bind_simple<std::_mem_fn<void (readerthread::*)(reader, synccontroller&)>(std::shared_ptr<aeirtuthread::readerthread>, reader, std::reference_wrapper<synccontroller>)>' /usr/gcc-4.7.4/lib/gcc/i586-pc-linux-gnu/4.7.4/../../../../include/c++/4.7.4/thread:133:9:   required 'std::thread::thread(_callable&&, _args&& ...) [with _callable = void (readerthread::*)(reader, synccontroller&); _args = {std::shared_ptr<readerthread>&, reader&, std::reference_wrapper<synccontroller>}]' ./aeirtu/aeirtu/main.cpp:155:96:   required here /usr/gcc-4.7.4/lib/gcc/i586-pc-linux-gnu/4.7.4/../../../../include/c++/4.7.4/type_traits:1834:9: error: no match call '(std::_mem_fn<void (readerthread::*)(reader, synccontroller&)>) (std::shared_ptr<readerthread>, reader, std::reference_wrapper<synccontroller>)' 

i can´t find out if error being caused use of std::ref on older compilers or different.

help appreciated fo find fix supported 4.7.4 , compile code.

gcc 4.7 doesn't seem able handle shared_ptr (or unique_ptr matter) provided object. works fine natural pointer, though - 1 possible solution replace thread creation following (if appropriate, of course):

std::thread th(&readerthread::start, &mythread, myreader, std::ref(synccontroller)); 

now, if not feasible , true allocated pointers needed, following replacement idea:

  std::thread th(                  [ptr, &synccontroller, myreader] () {                       ptr->start(myreader, synccontroller);                  }                 );  } 

in example, syncontroller passed reference, else value, same way in post.