Defined in header <cwchar> std::size_t mbrlen( const char* s, std::size_t n, std::mbstate_t* ps); Determines the size, in bytes, of the remainder of the multibyte character whose first byte is pointed to by s, given the current conversion state ps. This function is equivalent to the call std::mbrtowc(nullptr, s, n, ps?ps:&internal) for some hidden object internal of type std::mbstate_t, except that the expression ps is evaluated only once. Parameters s - pointer

Defined in header <cstdio> char* gets( char* str ); (until C++14) Reads stdin into given character string until a newline character is found or end-of-file occurs. Parameters str - character string to be written Return value str on success, NULL on failure. If the failure has been caused by end of file condition, additionally sets the eof indicator (see std::feof()) on stdin. If the failure has been caused by some other error, sets the error indicator (see std

Inside a class, declares members not bound to specific instances. Syntax static data_member (1) static member_function (2) 1) Declares a static data member. 2) Declares a static member function. Explanation Static members of a class are not associated with the objects of the class: they are independent objects with static storage duration or regular functions defined in namespace scope, only once in the program. The static keyword is only used with the declaration of a sta

static T infinity(); (until C++11) static constexpr T infinity(); (since C++11) Returns the special value "positive infinity", as represented by the floating-point type T. Only meaningful if std::numeric_limits<T>::has_infinity == true. In IEEE 754, the most common binary representation of floating-point numbers, the positive infinity is the value with all bits of the exponent set and all bits of the fraction cleared. Return value T std::numeric_limits<T>::infini

Defined in header <locale> class messages_base; The class std::messages_base provides a type definition which is inherited and used by the std::messages facets. Member types Member type Definition catalog /*unspecified signed integer type*/ Notes catalog was erroneously specified as int in C++11, this was corrected in LWG issue #2028 and included in C++14. See also messages implements retrieval of strings from message catalogs (class template)

Defined in header <type_traits> template< class T > struct is_union; (since C++11) Checks whether T is an union type. Provides the member constant value which is equal to true, if T is an union type . Otherwise, value is equal to false. Template parameters T - a type to check Helper variable template template< class T > constexpr bool is_union_v = is_union<T>::value; (since C++17) Inherited from std::integral_constant Member co

duration& operator+=(const duration& d); (1) duration& operator-=(const duration& d); (2) duration& operator*=(const rep& rhs); (3) duration& operator/=(const rep& rhs); (4) duration& operator%=(const rep& rhs); (5) duration& operator%=(const duration& rhs); (6) Performs compound assignments between two durations with the same period or between a duration and a tick count value. If rep_ is the member variable

bool valid() const; (since C++11) Checks if the future refers to a shared state. This is the case only for futures that were not default-constructed or moved from (i.e. returned by std::promise::get_future(), std::packaged_task::get_future() or std::async()) until the first time get() or share() is called. The behavior is undefined if any member function other than the destructor, the move-assignment operator, or valid is called on a future that does not refer to shared state (although

Defined in header <cwctype> std::wint_t towupper( std::wint_t ch ); Converts the given wide character to uppercase, if possible. Parameters ch - wide character to be converted Return value Uppercase version of ch or unmodified ch if no uppercase version is listed in the current C locale. Notes Only 1:1 character mapping can be performed by this function, e.g. the uppercase form of 'ß' is (with some exceptions) the two-character string "SS", which cannot be

Defined in header <ios> std::ios_base& showpoint( std::ios_base& str ); (1) std::ios_base& noshowpoint( std::ios_base& str ); (2) Enables or disables the unconditional inclusion of the decimal point character in floating-point output. Has no effect on input. 1) enables the showpoint flag in the stream str as if by calling str.setf(std::ios_base::showpoint). 2) disables the showpoint flag in the stream str as if by calling str.unsetf(std::ios_base::show