Consider a few vectors v1,v2,v3 to which you need to apply one function (for example clear()).
vector <int> v1;
vector <int> v2;
vector <int> v3;
v1.clear();
v2.clear();
v3.clear();
Can I do it in one line? So I need something like that
someHOF(clear(), ls[v1, v2, v3]);
Two lines:
for (auto v : {&v1, &v2, &v3})
v->clear();
You could also make a function for this, but I don't see any benefit in doing so. And calling the function becomes complicated if the method you call is overloaded.
template <typename T, typename ...P>
void apply(T func, P &&... targets)
{
(void((std::forward<P>(targets).*func)()), ...);
}
int main()
{
std::vector<int> v1, v2, v3;
apply(&std::vector<int>::clear, v1, v2, v3);
}
You could use std::for_each from the algorithms library along with a lambda. This really doesn't improve on HolyBlackCat's initial suggestion, though.
#include <vector>
#include <algorithm>
int main() {
using vec = std::vector<int>;
vec v1 { 2, 3, 4 };
vec v2 { 5, 6, 7 };
vec v3 { 8, 9 };
std::vector<vec*> v4 { &v1, &v2, &v3 };
std::for_each(v4.begin(), v4.end(), [](auto &i){i->clear();});
return 0;
}
