How do I erase an element from std::vector<> by index?
I have a std::vector<int>, and I want to delete the n'th element. How do I do that?
std::vector<int> vec;
vec.push_back(6);
vec.push_back(-17);
vec.push_back(12);
vec.erase(???);
To delete a single element, you could do:
std::vector<int> vec;
vec.push_back(6);
vec.push_back(-17);
vec.push_back(12);
// Deletes the second element (vec[1])
vec.erase(vec.begin() + 1);
Or, to delete more than one element at once:
// Deletes the second through third elements (vec[1], vec[2])
vec.erase(vec.begin() + 1, vec.begin() + 3);
The erase method on std::vector is overloaded, so it's probably clearer to call
vec.erase(vec.begin() + index);
when you only want to erase a single element.
template <typename T>
void remove(std::vector<T>& vec, size_t pos)
{
std::vector<T>::iterator it = vec.begin();
std::advance(it, pos);
vec.erase(it);
}