Synopsis

An iterator is used, then compared with end()

Enabled by default

Yes

Severity/Certainty

Medium/Medium

Full description

An iterator is used, then compared with end(). Using an iterator requires that it does not point to the end of a container. Subsequently comparing it with end() or rend() means that it might have been invalid at the point of dereference.

Coding standards

Code examples

The following code example fails the check and will give a warning:

#include <vector>

int example(std::vector<int>& vec,
            std::vector<int>::iterator iter) {

  *iter = 4;  //line 9 asserts that iter may be
              //at the end of vec
  
  if (iter != vec.end()) {
    return 0;
  }
  return 1;
}

The following code example passes the check and will not give a warning about this issue:

#include <vector>

int example(std::vector<int>& vec,
            std::vector<int>::iterator iter) {

  if (iter != vec.end()) {
    *iter = 4;
  }
              
  if (iter != vec.end()) {
    return 0;
  }
  return 1;
}