std::deque<T,Allocator>::push_front
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|   void push_front( const T& value );  | 
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|   void push_front( T&& value );  | 
(since C++11) | |
Prepends the given element value to the beginning of the container. 
All iterators, including the past-the-end iterator, are invalidated. No references are invalidated.
Parameters
| value | - | the value of the element to prepend | 
Return value
(none)
Complexity
Constant.
Exceptions
If an exception is thrown, this function has no effect (strong exception guarantee).
See also
|    (C++11)  | 
   constructs an element in-place at the beginning   (public member function)  | 
|    adds an element to the end  (public member function)  | |
|    removes the first element   (public member function)  |