Declarations introduce (or re-introduce) names into the C++ program. Each kind of entity is declared differently. Definitions are declarations that are sufficient to use the entity identified by the name. A declaration is one of the following: Function declaration Template declaration Explicit template instantiation Explicit template specialization Namespace definition Linkage specification Attribute declaration (attr ;) (since C++11) Empty declaration (;) Block declaration (a

Declares a named variable as a reference, that is, an alias to an already-existing object or function. Syntax A reference variable declaration is any simple declaration whose declarator has the form. & attr(optional) declarator (1) && attr(optional) declarator (2) (since C++11) 1) Lvalue reference declarator: the declaration S& D; declares D as an lvalue reference to the type determined by decl-specifier-seq S. 2) Rvalue reference declarator: the declaration S

nested_exception(); (1) (since C++11) nested_exception( const nested_exception& other ) = default; (2) (since C++11) Constructs new nested_exception object. 1) Default constructor. Stores an exception object obtained by calling std::current_exception() within the new nested_exception object. 2) Copy constructor. Initializes the object with the exception stored in other. Parameters other - nested exception to initialize the contents with Exceptions noexcept sp

template< class Key, class Hash, class KeyEqual, class Alloc > void swap( unordered_set<Key,Hash,KeyEqual,Alloc>& lhs, unordered_set<Key,Hash,KeyEqual,Alloc>& rhs ); (since C++11) Specializes the std::swap algorithm for std::unordered_set. Swaps the contents of lhs and rhs. Calls lhs.swap(rhs). Parameters lhs, rhs - containers whose contents to swap Return value (none). Complexity Constant. Exceptions noexcept specification: noe

Defined in header <ctime> std::clock_t clock(); Returns the approximate processor time used by the process since the beginning of an implementation-defined era related to the program's execution. To convert result value to seconds divide it by CLOCKS_PER_SEC. Only the difference between two values returned by different calls to std::clock is meaningful, as the beginning of the std::clock era does not have to coincide with the start of the program. std::clock time may advanc

template< class Rep, class Period > std::future_status wait_for( const std::chrono::duration<Rep,Period>& timeout_duration ) const; (since C++11) Waits for the result to become available. Blocks until specified timeout_duration has elapsed or the result becomes available, whichever comes first. Returns value identifies the state of the result. A steady clock is used to measure the duration. This function may block for longer than timeout_duration due to scheduling or res

Defined in header <locale> template< class Codecvt, class Elem = wchar_t, class Wide_alloc = std::allocator<Elem>, class Byte_alloc = std::allocator<char> > class wstring_convert; (since C++11) Class template std::wstring_convert performs conversions between byte string std::string and wide string std::basic_string<Elem>, using an individual code conversion facet Codecvt. std::wstring_convert assumes ownership of the con

typedef /*implementation defined*/ iostate; static constexpr iostate goodbit = 0; static constexpr iostate badbit = /*implementation defined*/ static constexpr iostate failbit = /*implementation defined*/ static constexpr iostate eofbit = /*implementation defined*/ Specifies stream state flags. It is a BitmaskType, the following constants are defined: Constant Explanation goodbit no error badbit irrecoverable stream error failbit input/output operation failed

(1) iterator insert( iterator pos, const T& value ); (until C++11) iterator insert( const_iterator pos, const T& value ); (since C++11) iterator insert( const_iterator pos, T&& value ); (2) (since C++11) (3) void insert( iterator pos, size_type count, const T& value ); (until C++11) iterator insert( const_iterator pos, size_type count, const T& value ); (since C++11) (4) template< class InputIt > void insert( iterator pos, InputIt f

Defined in header <regex> template< class OutputIt, class BidirIt, class Traits, class CharT, class STraits, class SAlloc > OutputIt regex_replace( OutputIt out, BidirIt first, BidirIt last, const std::basic_regex<CharT,Traits>& re, const std::basic_string<CharT,STraits,SAlloc>& fmt, std::regex_constants::match_flag_type flags = std::re