reference back(); (since {std}) const_reference back() const; (since {std}) Returns reference to the last element in the container. Calling back on an empty container is undefined. Parameters (none). Return value Reference to the last element. Complexity Constant. Notes For a container c, the expression return c.back(); is equivalent to { auto tmp = c.end(); --tmp; return *tmp; } Example The following code uses back to display the last element of a std::dynarray<

Usage alternative operators: as an alternative for ~

Defined in header <csignal> void (*signal( int sig, void (*handler) (int))) (int); Sets the error handler for signal sig. The signal handler can be set so that default handling will occur, signal is ignored, or a user-defined function is called. When signal handler is set to a function and a signal occurs, it is implementation defined whether std::signal(sig, SIG_DFL) will be executed immediately before the start of signal handler. Also, the implementation can prevent some

Usage boolean literal

Defined in header <atomic> atomic_flag(); (1) (since C++11) atomic_flag( const atomic_flag& ) = delete; (2) (since C++11) Constructs a new std::atomic_flag. 1) Trivial default constructor, initializes std::atomic_flag to unspecified state. 2) The copy constructor is deleted; std::atomic_flag is not copyable. In addition, std::atomic_flag can be value-initialized to clear state with the expression ATOMIC_FLAG_INIT. For an atomic_flag with static storage duration, t

result_type a() const; (1) (since C++11) result_type b() const; (2) (since C++11) Returns the parameters the distribution has been constructed with. 1) Returns the a distribution parameter. It defines the minimum possibly generated value. The default value is ​0​. 2) Returns the b distribution parameter. It defines the maximum possibly generated value. The default value is std::numeric_limits<IntType>::max() Parameters (none). Return value 1) The a distribution par

template< class... Args > void emplace_front( Args&&... args ); (since C++11) Inserts a new element to the beginning of the container. The element is constructed through std::allocator_traits::construct, which typically uses placement-new to construct the element in-place at the location provided by the container. The arguments args... are forwarded to the constructor as std::forward<Args>(args).... No iterators or references are invalidated. Parameters args -

valarray<T> operator+() const; (1) valarray<T> operator-() const; (2) valarray<T> operator~() const; (3) valarray<bool> operator!() const; (4) Applies unary operators to each element in the numeric array. Parameters (none). Return value A numeric array containing elements with values obtained by applying corresponding operator to the values in *this. Exceptions (none). Notes Each of the operators can only be instantiated if the follo

bool try_lock(); (since C++11) Tries to lock the mutex. Returns immediately. On successful lock acquisition returns true, otherwise returns false. This function is allowed to fail spuriously and return false even if the mutex is not currently locked by any other thread. A thread may call try_lock on a recursive mutex repeatedly. Successful calls to try_lock increment the ownsership count: the mutex will only be released after the thread makes a matching number of calls to unlock. The ma

key_equal key_eq() const; (since C++11) Returns the function that compares keys for equality. Parameters (none). Return value The key comparison function. Complexity Constant. See also hash_function returns function used to hash the keys (public member function)