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#include <boost/program_options.hpp>
#include <iostream>

namespace opt = boost::program_options;

int main(int argc, char *argv[])
{
    // Constructing an options describing variable and giving it a
    // textual description "All options".
    opt::options_description desc("All options");

    // When we are adding options, first parameter is a name
    // to be used in command line. Second parameter is a type
    // of that option, wrapped in value<> class. Third parameter
    // must be a short description of that option.
    desc.add_options()
        ("apples", opt::value<int>(), "how many apples do you have")
        ("oranges", opt::value<int>(), "how many oranges do you have")
        ("help", "produce help message")
    ;

    // Variable to store our command line arguments.
    opt::variables_map vm;

    // Parsing and storing arguments.
    opt::store(opt::parse_command_line(argc, argv, desc), vm);

    // Must be called after all the parsing and storing.
    opt::notify(vm);

    if (vm.count("help")) {
        std::cout << desc << "\n";
        return 1;
    }

    std::cout << "Fruits count: "
        << vm["apples"].as<int>() + vm["oranges"].as<int>()
        << std::endl;

} // end of `main`

cmake_minimum_required(VERSION 3.3)
project(BoostTest)

FIND_PACKAGE(Boost COMPONENTS program_options REQUIRED)
INCLUDE_DIRECTORIES(${Boost_INCLUDE_DIRS})

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++14")
#set(CMAKE_CXX_FLAGS "-lboost_program_options")

set(SOURCE_FILES main.cpp)
add_executable(BoostTest ${SOURCE_FILES})
target_link_libraries(BoostTest ${Boost_LIBRARIES} -lpthread)
target_link_libraries(BoostTest ${Boost_LIBRARIES} -lboost_program_options)

cmake . 
make

#include <boost/thread/mutex.hpp>
#include <boost/thread/locks.hpp>
#include <boost/thread.hpp>
#include <iostream>

namespace with_sync {

int shared_i = 0;
boost::mutex i_mutex;

void do_inc() {
    for (std::size_t i = 0; i < 30000; ++i) {
        int i_snapshot;
        {   // Critical section begin.
            boost::lock_guard<boost::mutex> lock(i_mutex);
            i_snapshot = ++shared_i;
        }   // Critical section end.
        std::cout<<i_snapshot<<std::endl;
        // Do some work with i_snapshot.
        // ...
        (void)i_snapshot;
    }
}

void do_dec() {
    for (std::size_t i = 0; i < 30000; ++i) {
        int i_snapshot;
        {   // Critical section begin.
            boost::lock_guard<boost::mutex> lock(i_mutex);
            i_snapshot = -- shared_i;
        }   // Critical section end.
            std::cout<<i_snapshot<<std::endl;
        // Do some work with i_snapshot.
        // ...
        (void) i_snapshot;
    }
}

int run() {
    boost::thread t1(&do_inc);
    boost::thread t2(&do_dec);

    t1.join();
    t2.join();

    assert(shared_i == 0);
    std::cout << "shared_i == " << shared_i;
}

} // namespace without_sync
int main() {
with_sync::run();
return 0; };

target_link_libraries(BoostTest ${Boost_LIBRARIES} -lpthread)
target_link_libraries(BoostTest ${Boost_LIBRARIES} -lboost_thread)