Defined in header <cstdlib> std::size_t wcstombs( char* dst, const wchar_t* src, std::size_t len); Converts a sequence of wide characters from the array whose first element is pointed to by src to its narrow multibyte representation that begins in the initial shift state. Converted characters are stored in the successive elements of the char array pointed to by dst. No more than len bytes are written to the destination array. Each character is converted as if by a call to s

Defined in header <iterator> template< class C > auto begin( C& c ) -> decltype(c.begin()); (1) (since C++11) template< class C > auto begin( const C& c ) -> decltype(c.begin()); (1) (since C++11) (2) template< class T, std::size_t N > T* begin( T (&array)[N] ); (since C++11) (until C++14) template< class T, std::size_t N > constexpr T* begin( T (&array)[N] ); (since C++14) template< class C > constex

protected: virtual pos_type seekpos(pos_type sp, std::ios_base::openmode which = std::ios_base::in | std::ios_base::out ); Repositions std::basic_streambuf::gptr and/or std::basic_streambuf::pptr, if possible, to the position indicated by sp. Effectively executes seekoff(off_type(sp), std::ios_base::beg, which). Parameters sp - stream position, such as one obtained by seekoff() or seekpos() which - defines whether the input sequences, the output se

Requirements Trivial copy constructor Trivial move constructor Trivial copy assignment operator Trivial move assignment operator Trivial destructor No virtual functions or virtual base classes All (non-static) members and base classes are TriviallyCopyable Scalar types and arrays of TriviallyCopyable objects are TriviallyCopyable as well, as well as the const-qualified (but not volatile-qualified) versions of such types. See also is_trivially_copyable (C++11) checks if

Defined in header <locale> class ctype_base; The class std::ctype_base lists the character classification categories which are inherited by the std::ctype facets. Member types mask unspecified BitmaskType (enumeration, integer type, or bitset) (typedef) Member constants space [static] the value of mask identifying whitespace character classification (public static member constant) print [static] the value of mask identifying printable character class

Rule of three If a class requires a user-defined destructor, a user-defined copy constructor, or a user-defined copy assignment operator, it almost certainly requires all three. Because C++ copies and copy-assigns objects of user-defined types in various situations (passing/returning by value, manipulating a container, etc), these special member functions will be called, if accessible, and if they are not user-defined, they are implicitly-defined by the compiler. The implicitly-defined speci

Defined in header <cmath> float tgamma( float arg ); (1) (since C++11) double tgamma( double arg ); (2) (since C++11) long double tgamma( long double arg ); (3) (since C++11) double tgamma( Integral arg ); (4) (since C++11) 1-3) Computes the gamma function of arg. 4) A set of overloads or a function template accepting an argument of any integral type. Equivalent to 2) (the argument is cast to double). Parameters arg - value of a f

Defined in header <scoped_allocator> template< class OuterAlloc, class... InnerAlloc > class scoped_allocator_adaptor : public OuterAlloc; (since C++11) The std::scoped_allocator_adaptor class template is an allocator which can be used with multilevel containers (vector of sets of lists of tuples of maps, etc). It is instantiated with one outer allocator type OuterAlloc and zero or more inner allocator types InnerAlloc.... A container constructed directly with a scope

The random number library provides classes that generate random and pseudo-random numbers. These classes include: Random number engines (both pseudo-random number generators, which generate integer sequences with a uniform distribution, and true random number generators if available) Random number distributions (e.g. uniform, normal, or poisson distributions) which convert the output of random number engines into various statistical distributions Engines and distributions are designed to

Defined in header <cmath> int fpclassify( float arg ); (1) (since C++11) int fpclassify( double arg ); (2) (since C++11) int fpclassify( long double arg ); (3) (since C++11) int fpclassify( Integral arg ); (4) (since C++11) 1-3) Categorizes floating point value arg into the following categories: zero, subnormal, normal, infinite, NAN, or implementation-defined category. 4) A set of overloads or a function template accepting the from argument of any inte