How do I remove the first occurrence of a value from a vector?

Question

I\'m trying to get a single element from a vector and push it to the back of the vector then remove it so I won\'t have an empty section in memory. The erase-remove idiom ca

Answer 1

Find it first, then erase it:

auto it = std::find(v.begin(),v.end(),3);
// check that there actually is a 3 in our vector
if (it != v.end()) {
  v.erase(it);
}

Answer 2

If you don't care about maintaining the ordering of the elements in the vector, you can avoid the copy of the "tail" of remaining elements on erase:

auto it = std::find(v.begin(), v.end(), 3);
if (it != v.end()) {
  std::iter_swap(it, v.end() - 1);
  v.erase(v.end() - 1);
}