cppfx - cpp/c++, b2 build

c++ now: c++ coroutines with boost::cobalt

This program uses boost::cobalt to manage c++ coroutines.

#include <boost/cobalt.hpp>
#include <iostream>
#include <chrono>

namespace cobalt = boost::cobalt;
using std::chrono_literals::operator""s;

class bob_box
{
public:
	virtual ~bob_box() = default;
public:
	cobalt::promise<float> fn(float x) const
	{
		co_return x*x;
	}
	cobalt::generator<float> func(float x) const
	{
		float i = 1.5f;
		while (true)
			co_yield x*i++;
	}
};

cobalt::main co_main(int argc, char * argv[])
{
	auto bob = bob_box{};
	std::cout << co_await bob.fn(2.5f) << std::endl;	// 6.25
	auto start = std::chrono::system_clock::now();
	auto rco = bob.func(1.5f);
	while (auto now = std::chrono::system_clock::now() < start + 2.7s && rco)
	{
		std::cout << "=> " << co_await rco << std::endl;
		std::this_thread::sleep_for(0.8s);
	}
	co_return 0;
}

6.25
=> 2.25
=> 3.75
=> 5.25
=> 6.75