RosettaCodeData/Task/Queue-Usage/C++/queue-usage-1.cpp

47 lines
1.2 KiB
C++

#include <queue>
#include <cassert> // for run time assertions
int main()
{
std::queue<int> q;
assert( q.empty() ); // initially the queue is empty
q.push(1); // add an element
assert( !q.empty() ); // now the queue isn't empty any more
assert( q.front() == 1 ); // the first element is, of course, 1
q.push(2); // add another element
assert( !q.empty() ); // it's of course not empty again
assert( q.front() == 1 ); // the first element didn't change
q.push(3); // add yet an other element
assert( !q.empty() ); // the queue is still not empty
assert( q.front() == 1 ); // and the first element is still 1
q.pop(); // remove the first element
assert( !q.empty() ); // the queue is not yet empty
assert( q.front() == 2); // the first element is now 2 (the 1 is gone)
q.pop();
assert( !q.empty() );
assert( q.front() == 3);
q.push(4);
assert( !q.empty() );
assert( q.front() == 3);
q.pop();
assert( !q.empty() );
assert( q.front() == 4);
q.pop();
assert( q.empty() );
q.push(5);
assert( !q.empty() );
assert( q.front() == 5);
q.pop();
assert( q.empty() );
}