A function named test
takes std::function<>
as its parameter.
template<typename R, typename ...A>
void test(std::function<R(A...)> f)
{
// ...
}
But, if I do the following:
void foo(int n) { /* ... */ }
// ...
test(foo);
Compiler(gcc 4.6.1) says no matching function for call to test(void (&)(int))
.
To make the last line test(foo)
compiles and works properly, how can I modify the test()
function? In test()
function, I need f
with type of std::function<>
.
I mean, is there any template tricks to let compiler determine the signature of function(foo
in example), and convert it to std::function<void(int)>
automatically?
I want to make this work for lambdas(both stated and stateless) as well.
It looks like you want to use overloading
template<typename R, typename ...A>
void test(R f(A...))
{
test(std::function<R(A...)>(f));
}
This simple implementation will accept most if not all the functions you will try to pass. Exotic functions will be rejected (like void(int...)
). More work will give you more genericity.