How to convert a lambda to an std::function using templates
- by retep998
Basically, what I want to be able to do is take a lambda with any number of any type of parameters and convert it to an std::function.
I've tried the following and neither method works.
std::function([](){});//Complains that std::function is missing template parameters
template <typename T> void foo(function<T> f){}
foo([](){});//Complains that it cannot find a matching candidate
The following code does work however, but it is not what I want because it requires explicitly stating the template parameters which does not work for generic code.
std::function<void()>([](){});
I've been mucking around with functions and templates all evening and I just can't figure this out, so any help would be much appreciated.
As mentioned in a comment, the reason I'm trying to do this is because I'm trying to implement currying in C++ using variadic templates. Unfortunately, this fails horribly when using lambdas. For example, I can pass a standard function using a function pointer.
template <typename R, typename...A>
void foo(R (*f)(A...)) {}
void bar() {}
int main() {
foo(bar);
}
However, I can't figure out how to pass a lambda to such a variadic function. Why I'm interested in converting a generic lambda into an std::function is because I can do the following, but it ends up requiring that I explicitly state the template parameters to std::function which is what I am trying to avoid.
template <typename R, typename...A>
void foo(std::function<R(A...)>) {}
int main() {
foo(std::function<void()>([](){}));
}
