Specifies that an instance of the type can be default-constructed in-place by a given allocator. Requirements The type T is DefaultInsertable into the Container X whose value_type is identical to T if, given. A an allocator type m an lvalue of type A p the pointer of type T* prepared by the container where X::allocator_type is identical to std::allocator_traits<A>::rebind_alloc<T>, the following expression is well-formed: std::allocator_traits<A>::construct(m,

Defined in header <mutex> struct defer_lock_t { }; (since C++11) struct try_to_lock_t { }; (since C++11) struct adopt_lock_t { }; (since C++11) std::defer_lock_t, std::try_to_lock_t and std::adopt_lock_t are empty struct tag types used to specify locking strategy for std::lock_guard, std::unique_lock and std::shared_lock. Type Effect(s) defer_lock_t do not acquire ownership of the mutex try_to_lock_t try to acquire ownership of the mutex without block

T* data(); (since C++11) const T* data() const; (since C++11) Returns pointer to the underlying array serving as element storage. The pointer is such that range [data(); data() + size()) is always a valid range, even if the container is empty. Parameters (none). Return value Pointer to the underlying element storage. For non-empty containers, returns &front(). Complexity Constant. Exceptions noexcept specification: noexcept See also front access the first

Defined in header <functional> template< class T > struct divides; (until C++14) template< class T = void > struct divides; (since C++14) Function object for performing division. Effectively calls operator/ on two instances of type T. Specializations The standard library provides a specialization of std::divides when T is not specified, which leaves the parameter types and return type to be deduced. divides<void> function object implementing

size_type count( const Key& key ) const; (1) template< class K > size_type count( const K& x ) const; (2) (since C++14) 1) Returns the number of elements with key key, which is either 1 or 0 since this container does not allow duplicates 2) Returns the number of elements with key that compares equivalent to the value x. This overload only participates in overload resolution if the qualified-id Compare::is_transparent is valid and denotes a type. They allow calling

void freeze(bool flag = true); If the stream is using a dynamically-allocated array for output, disables (flag == true) or enables (flag == false) automatic allocation/deallocation of the buffer. Effectively calls rdbuf()->freeze(flag). Notes After a call to str(), dynamic streams become frozen automatically. A call to freeze(false) is required before exiting the scope in which this strstream object was created. otherwise the destructor will leak memory. Also, additional output to

Defined in header <algorithm> template< class InputIt, class Size, class OutputIt > OutputIt copy_n( InputIt first, Size count, OutputIt result ); (since C++11) Copies exactly count values from the range beginning at first to the range beginning at result, if count>0. Does nothing otherwise. Parameters first - the beginning of the range of elements to copy from count - number of the elements to copy result - the beginning of the destination rang

Defined in header <type_traits> template< class T > struct add_cv; (1) (since C++11) template< class T > struct add_const; (2) (since C++11) template< class T > struct add_volatile; (3) (since C++11) Provides the member typedef type which is the same as T, except it has a cv-qualifier added (unless T is a function, a reference, or already has this cv-qualifier). 1) adds both const and volatile. 2) adds const. 3) adds volatile. Member types

void reset(); (since C++11) Releases the reference to the managed object. After the call *this manages no object. Parameters (none). Return value (none). Exceptions noexcept specification: noexcept

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