利用lexical

获取线程id可直接调用**this_thread::get_id()**函数，可经std::cout打印到标准输出，但此时输出的却是十六进制的数，且不能通过普通int型变量保存，因此，需要用lexical_cast转换。

#include 
#include 

int print_thread_id()
{
    std::string str_thread_id = boost::lexical_cast(boost::this_thread::get_id());
	//std::cout << "thread id: " << strtol(str_thread_id.c_str(), NULL, 16) << std::endl;
	//std::cout << "concurrency: " << boost::thread::hardware_concurrency() << std::endl;
    return (int)strtol(str_thread_id.c_str(), NULL, 16);
}

int main()
{
	int current_thread_id = print_thread_id();

	return 0;
}