std::thread error (thread not member of std)

Question

I compiled & installed gcc4.4 using macports.

When I try to compile using -> g++ -g -Wall -ansi -pthread -std=c++0x main.cpp...:

 #include <thread>
 ...
  std::thread t(handle);
  t.join();
 ....

The compiler returns:

 cserver.cpp: In member function 'int CServer::run()':
 cserver.cpp:48: error: 'thread' is not a member of 'std'
 cserver.cpp:48: error: expected ';' before 't'
 cserver.cpp:49: error: 't' was not declared in this scope

But std::cout <<... compiles fine..

Can anyone help me?

Solution 1

gcc does not fully support std::thread yet:

http://gcc.gnu.org/projects/cxx0x.html

http://gcc.gnu.org/onlinedocs/libstdc++/manual/status.html

Use boost::thread in the meantime.

Edit

Although the following compiled and ran fine for me with gcc 4.4.3:

#include <thread>
#include <iostream>

struct F
{
  void operator() () const
  {
    std::cout<<"Printing from another thread"<<std::endl;
  }
};

int main()
{
  F f;
  std::thread t(f);
  t.join();

  return 0;
}

Compiled with

g++ -Wall -g -std=c++0x -pthread main.cpp

Output of a.out:

Printing from another thread

Can you provide the full code? Maybe there's some obscure issue lurking in those ...s?

Solution 2

Drop -ansi, it means -std=c++98, which you obviously don't want. It also causes macro __STRICT_ANSI__ to be defined and this may change the behavior of the headers, e.g. by disabling C++0x support.

Solution 3

I had the same issue on windows using MinGW. I found wrapper classes for in on github mingw-std-threads Including mingw.mutex.h, mingw.thread.h files to global MinGW directory fixed this issue. All I had to do is to include header file and my code stayed the same

#include "mingw.thread.h"

...
std::thread t(handle);
...