Defined in header <cmath> float round( float arg ); (1) (since C++11) double round( double arg ); (2) (since C++11) long double round( long double arg ); (3) (since C++11) double round( Integral arg ); (4) (since C++11) long lround( float arg ); (5) (since C++11) long lround( double arg ); (6) (since C++11) long lround( long double arg ); (7) (since C++11) long lround( Integral arg ); (8) (since C++11) long long llround( float arg );

Compares the arguments. Operator name Syntax Over​load​able Prototype examples (for class T) As member function As free (namespace) function equal to a == b Yes bool T::operator ==(const T2 &b) const; bool operator ==(const T &a, const T2 &b); not equal to a != b Yes bool T::operator !=(const T2 &b) const; bool operator !=(const T &a, const T2 &b); less than a < b Yes bool T::operator <(const T2 &b) const; bool operator <

Elaborated type specifiers may be used to refer to a previously-declared class name (class, struct, or union) or to a previously-declared enum name even if the name was hidden by a non-type declaration. They may also be used to declare new class names. Syntax class-key class-name (1) enum enum-name (2) class-key attr(optional) identifier ; (3) class-key - one of class, struct, union class-name - the name of a previously-declared class type, optionally qualified

Defined in header <ratio> template< class R1, class R2 > struct ratio_greater : std::integral_constant; If the ratio R1 is greater than than the ratio R2, provides the member constant value equal true. Otherwise, value is false. Helper variable template template< class R1, class R2 > constexpr bool ratio_greater_v = ratio_greater<R1, R2>::value; (since C++17) Inherited from std::integral_constant Member constants value [static] true

members of the primary template, unique_ptr<T> constexpr unique_ptr(); constexpr unique_ptr( nullptr_t ); (1) explicit unique_ptr( pointer p ); (2) unique_ptr( pointer p, /* see below */ d1 ); (3) unique_ptr( pointer p, /* see below */ d2 ); (4) unique_ptr( unique_ptr&& u ); (5) template< class U, class E > unique_ptr( unique_ptr<U, E>&& u ); (6) template< class U > unique_ptr( auto_ptr<U>&& u ); (7

reverse_iterator rend(); const_reverse_iterator rend() const; const_reverse_iterator crend() const; (since C++11) Returns a reverse iterator to the element following the last element of the reversed container. It corresponds to the element preceding the first element of the non-reversed container. This element acts as a placeholder, attempting to access it results in undefined behavior. Parameters (none). Return value Reverse iterator to the element following the last

Defined in header <locale> class codecvt_base; The class std::codecvt_base provides the conversion status constants which are inherited and used by the std::codecvt facets. Member types Member type Definition enum result { ok, partial, error, noconv }; Unscoped enumeration type Value Explanation ok conversion was completed with no error partial not all source characters were converted error encountered an invalid character noconv no conversio

explicit extreme_value_distribution( RealType a = 0.0, RealType b = 1.0 ); (1) (since C++11) explicit extreme_value_distribution( const param_type& params ); (2) (since C++11) Constructs a new distribution object. The first version uses a and b as the distribution parameters, the second version uses params as the distribution parameters. Parameters a - the a distribution parameter (location) b - the b distribution parameter (scale) params - the distribution

Defined in header <locale> public: CharT widen( char c ) const; (1) public: const char* widen( const char* beg, const char* end, CharT* dst ) const; (2) protected: virtual CharT do_widen( char c ) const; (3) protected: virtual const char* do_widen( const char* beg, const char* end, CharT* dst ) const; (4) 1,2) public member function, calls the protected virtual member function do_widen of the most derived class. 3) Converts the single-byte character c to

Defined in header <memory> void construct( pointer p, const_reference val ); (1) (until C++11) template< class U, class... Args > void construct( U* p, Args&&... args ); (2) (since C++11) Constructs an object of type T in allocated uninitialized storage pointed to by p, using placement-new. 1) Calls new((void *)p) T(val). 2) Calls ::new((void *)p) U(std::forward<Args>(args)...). Parameters p - pointer to allocated uninitialized storage va