boost/libs/thread/test/test_8455.cpp

// Copyright (C) 2013 Vicente Botet
//
//  Distributed under the Boost Software License, Version 1.0. (See accompanying
//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

#include <boost/thread/mutex.hpp>
boost::mutex mut;
void boostMutexImp1()
{
    boost::mutex::scoped_lock lock(mut);
    mut.unlock();  // A: with this X blocks
    //lock.unlock(); // No influence if used also if before A
}
void boostMutexImp2()
{
    boost::mutex::scoped_lock lock(mut); // X: blocks with A
}
int main()
{
    boostMutexImp1();
    boostMutexImp2();
    return 0;
}