std::deque<T,Allocator>::push_back (3) - Linux Manuals
void push_back( const T& value ); (1)
void push_back( T&& value ); (2) (since C++11)
Appends the given element value to the end of the container.
1) The new element is initialized as a copy of value.
2) value is moved into the new element.
All iterators, including the past-the-end iterator, are invalidated. No references are invalidated.
T must meet the requirements of CopyInsertable in order to use overload (1).
T must meet the requirements of MoveInsertable in order to use overload (2).
If an exception is thrown (which can be due to Allocator::allocate() or element copy/move constructor/assignment), this function has no effect (strong exception guarantee).
// Run this code
emplace_back constructs an element in-place at the end
push_front (public member function)
pop_back (public member function)