Why don't the standard C++ container adaptors provide a clear function?

Question

Does anyone know why std::queue, std::stack, and std::priority_queue don\'t provide a clear() member function? I have to fake one like this:

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Answer 1

You CAN clear queues (and std::stack and priority_queue), as long as you inherit from it. The container is intentionally left protected to allow this.

#include 

using namespace std;

class clearable_queue : public queue
{
public:
  void clear()
    {
      // the container 'c' in queues is intentionally left protected
      c.clear();
    }
};   

int main(int argc, char** argv)
{
  clearable_queue a;
  a.clear();
}