#include <memory>
#include <iostream>
template<class T>
struct call_with_pointer {
// last resort: T*
template<class Callable>
static auto call(Callable &callable, const std::shared_ptr<T> ¶m) -> decltype(callable(param.get())) {
return callable(param.get());
}
};
template<class T>
struct call_with_shared : public call_with_pointer<T> {
// best: call with shared_ptr<T>.
// SFINA
template<class Callable>
static auto call(Callable &callable, const std::shared_ptr<T> ¶m) -> decltype(callable(param)) {
return callable(param);
}
using call_with_pointer<T>::call;
};
class Test {
public:
bool operator () (int * x) {
return *x == 42;
}
};
using namespace std;
int main (int argc, const char * argv[])
{
{
Test t;
auto i = std::make_shared<int>(4);
auto x = call_with_shared<int>::call(t, i);
}
return 0;
}
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