A PriorityQueue is a list that always keeps its items sorted based on some rule, like smallest to largest. So, when you take an item out, you always get the one with the highest (or lowest) priority.

The declaration would go in the stack.h file, allowing the module’s user to make use of StackPtr_t, which is a pointer to StackStruct_t.The details of StackStruct_t ‘s members are completely hidden ...