How to check that an element is in a std::set?

Question

How do you check that an element is in a set?

Is there a simpler equivalent of the following code:

myset.find(x) != myset.end() 

Answer 1

The typical way to check for existence in many STL containers such as std::map, std::set, ... is:

const bool is_in = container.find(element) != container.end(); 

Answer 2

Another way of simply telling if an element exists is to check the count()

if (myset.count(x)) {    // x is in the set, count is 1 } else {    // count zero, i.e. x not in the set } 

Most of the times, however, I find myself needing access to the element wherever I check for its existence.

So I'd have to find the iterator anyway. Then, of course, it's better to simply compare it to end too.

set< X >::iterator it = myset.find(x); if (it != myset.end()) {    // do something with *it } 

C++ 20

In C++20 set gets a contains function, so the following becomes possible as mentioned at: https://stackoverflow.com/a/54197839/895245

if (myset.contains(x)) {   // x is in the set } else {   // no x  }