Defined in header <type_traits> template< class T > struct has_virtual_destructor; (since C++11) If T is a type with a virtual destructor, provides the member constant value equal true. For any other type, value is false. If T is a non-union class type, T shall be a complete type; otherwise, the behavior is undefined. Helper variable template template< class T > constexpr bool has_virtual_destructor_v = has_virtual_destructor<T>::value; (since C+

Usage thread local storage duration specifier (since C++11)

The preprocessor is executed at translation phase 4, before the compilation. The result of preprocessing is a single file which is then passed to the actual compiler. Directives The preprocessing directives control the behavior of the preprocessor. Each directive occupies one line and has the following format: # character preprocessing instruction (one of define, undef, include, if, ifdef, ifndef, else, elif, endif, line, error, pragma) [1] arguments (depends on the instruction) line b

Defined in header <chrono> constexpr std::chrono::nanoseconds operator "" ns(unsigned long long nsec); (1) (since C++14) constexpr std::chrono::duration</*unspecified*/, std::nano> operator "" ns(long double nsec); (2) (since C++14) Forms a std::chrono::duration literal representing nanoseconds. 1) integer literal, returns exactly std::chrono::nanoseconds(nsec) 2) floating-point literal, returns a floating-point duration equivalent

Defined in header <cwchar> int vwscanf( const wchar_t* format, va_list vlist ); (1) (since C++11) int vfwscanf( std::FILE* stream, const wchar_t* format, va_list vlist ); (2) (since C++11) int vswscanf( const wchar_t* buffer, const wchar_t* format, va_list vlist ); (3) (since C++11) Reads data from the a variety of sources, interprets it according to format and stores the results into locations defined by vlist. 1) Reads the data from stdin 2) Reads the data

static int compare( const char_type* s1, const char_type* s2, std::size_t count ); Compares the first count characters of the character strings s1 and s2. The comparison is done lexicographically. If count is zero, strings are considered equal. Parameters s1, s2 - pointers to character strings to compare count - the number of characters to compare from each character string Return value Negative value if s1 is less than s2. ​0​ if s1 is equal to s2. Positive value if

Defined in header <complex> template< class T > complex<T> polar( const T& r, const T& theta = 0 ); Returns a complex number with magnitude r and phase angle theta. The behavior is undefined if r is negative or NaN, or if theta is infinite (since C++17) Parameters r - magnitude theta - phase angle Return value a complex number determined by r and theta. See also abs(std::complex) returns the magnitude of a complex number (f

void wait() const; (since C++11) Blocks until the result becomes available. valid() == true after the call. The behavior is undefined if valid()== false before the call to this function. Parameters (none). Return value (none). Exceptions (none). Notes The implementations are encouraged to detect the case when valid == false before the call and throw a std::future_error with an error condition of std::future_errc::no_state. Example #include <iostream> #include <

Defined in header <future> const std::error_category& future_category(); (since C++11) Obtains a reference to the static error category object for future object errors. The object is required to override the virtual function error_category::name() to return a pointer to the string "future". It is used to identify error codes provided in the exceptions of type std::future_error. Parameters (none). Return value A reference to the static object of unspecified runtime

template< size_t I, class T, size_t N > constexpr T& get( array<T,N>& a ); (1) (since C++11) template< size_t I, class T, size_t N > constexpr T&& get( array<T,N>&& a ); (2) (since C++11) template< size_t I, class T, size_t N > constexpr const T& get( const array<T,N>& a ); (3) (since C++11) template< size_t I, class T, size_t N > constexpr const T&& get( const array<T,N>&& a );