Why doesn't std::queue support a clear() function?

Question

I have requirement: for a function, I get the input as a stream of numbers. I mean, the function keeps on getting called with single number in each call. I am using std::q

Answer 1

According to http://www.cplusplus.com/reference/stl/queue/,

queues are implemented as containers adaptors, which are classes that use an encapsulated object of a specific container class as its underlying container, providing a specific set of member functions to access it elements.

which means that the queue uses an already existing container, and is just really is an interface to this container as a FIFO queue.

This means queues are not meant to be cleared. If you need to clear a queue, this means you actually need to use an object that is not a queue, and therefore you should instead use the actual underlying container type, being a deque by default.