I agree. These days I can't even imagine programming in C++ without using STL. It still has some weird ergonomics at some places though. For example - instead of a simple vector.contains(something) we have to write this
std::vector<T> x_Vec;
if (!(x_Vec.find(another_x) == std::vector<T>::npos) {
//some code
}
The first snippet you wrote makes sense for string, but not for vector. For vector, you'd need to do:
if (x_Vec.find(another_x) != x_Vec.end()) {
//some code
}
The reason why vector doesn't have contains() is because it would be an O(N) operation for a vector. STL is generally designed in such a way that, when something needs to do an O(N) lookup, it has to deal with iterators, making the iteration happening in the background a bit more explicit.
But, for example, for std::set and map, you can just do:
if (a_set.count(x)) { ... }
It's not a good pattern for multiset and multimap, since it won't stop at the first occurrence. C++20 finally added contains() for that reason - but, again, only to associative containers.
Indeed! Which is why find() is not a member function on vector (so my snippet above is wrong - I just missed that part). It's a global function, so you need to do:
if (find(x, v.begin(), v.end()) != v.end()) ...
For maps and sets, find is a member function though. Same principle - if it is implemented in some optimized way, the class provides it directly, but not otherwise.
