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// launch::async vs launch::deferred
#include <iostream> // std::cout
#include <future> // std::async, std::future, std::launch
#include <chrono> // std::chrono::milliseconds
#include <thread> // std::this_thread::sleep_for
void print_ten (char c, int ms) {
for (int i=0; i<10; ++i) {
std::this_thread::sleep_for (std::chrono::milliseconds(ms));
std::cout << c;
}
}
int main ()
{
std::cout << "with launch::async:\n";
std::future<void> foo = std::async (std::launch::async,print_ten,'*',100);
std::future<void> bar = std::async (std::launch::async,print_ten,'@',200);
// async "get" (wait for foo and bar to be ready):
foo.get();
bar.get();
std::cout << "\n\n";
std::cout << "with launch::deferred:\n";
foo = std::async (std::launch::deferred,print_ten,'*',100);
bar = std::async (std::launch::deferred,print_ten,'@',200);
// deferred "get" (perform the actual calls):
foo.get();
bar.get();
std::cout << '\n';
return 0;
}
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