I want to call a method (for this example std::thread constructor) with lambda function, passing int value:
int a=10;
std::thread _testThread = thread([a](int _a){
//do stuff using a or _a ?
});
_testThread.detach();
I don't know how to properly write such function, I get this error: C2064: term does not evaluate to a function taking 0 arguments
std::thread
takes a callable object as well as any arguments to pass to it. If you give no arguments, std::thread
will try to call that object with no arguments, hence the error.
If you need a parameter:
std::thread _testThread{[a](int _a) {
std::cout << a << ' ' << _a; //prints main's a, followed by somethingThatWillBe_a
}, somethingThatWillBe_a};
If you're just trying to use main
's a
, it's already captured:
std::thread _testThread{[a] {
std::cout << a; //prints main's a
}};
I would also recommend being super careful if you think you need to detach a thread. If there's any possibility of joining the thread instead, go for it.