Check the below code.
#include <future>
template <class F, class... Args>
void do_something(F f, Args... args) {
using return_type = typename std::result_of<F(Args...)>::type;
// Why below gives an error?
std::packaged_task<return_type(Args...)> task(f, args...);
}
int func(int a, int b) {
}
int main() {
do_something(func, 1, 2);
}
The packaged_task constructor gives a following error.
error: no matching function for call to 'std::packaged_task<int(int, int)>::packaged_task(int (*&)(int, int), int&, int&)'
8 | std::packaged_task<return_type(Args...)> task(f, args...);
The thing I don't understand is that why f and args became a reference type in the constructor? The Args... were int, int types whereas args... just became int&, int&. Where is this coming from?
packaged_task do not have the signature you want.
compiler is saying there is no such function. (probably with candidates below it)