Defined in header <cstdlib> int mblen( const char* s, std::size_t n ); Determines the size, in bytes, of the multibyte character whose first byte is pointed to by s. If s is a null pointer, resets the global conversion state and determined whether shift sequences are used. This function is equivalent to the call std::mbtowc((wchar_t*)0, s, n), except that conversion state of std::mbtowc is unaffected. Notes Each call to mblen updates the internal global conversion state

Returns the result of specific arithmetic operation. Operator name Syntax Over​load​able Prototype examples (for class T) Inside class definition Outside class definition unary plus +a Yes T T::operator+() const; T operator+(const T &a); unary minus -a Yes T T::operator-() const; T operator-(const T &a); addition a + b Yes T T::operator+(const T2 &b) const; T operator+(const T &a, const T2 &b); subtraction a - b Yes T T::operator-

Defined in header <cwctype> int iswalpha( std::wint_t ch ); Checks if the given wide character is an alphabetic character, i.e. either an uppercase letter (ABCDEFGHIJKLMNOPQRSTUVWXYZ), a lowercase letter (abcdefghijklmnopqrstuvwxyz) or any alphabetic character specific to the current locale. Parameters ch - wide character Return value Non-zero value if the wide character is a alphabetic character, 0 otherwise. Example #include <iostream> #include &l

Usage friend specifier

An AllocatorAwareContainer is a Container that holds an instance of an Allocator and uses that instance to allocate and deallocate memory in all of its member functions. The following rules apply to object construction. Copy constructors of AllocatorAwareContainers obtain their instances of the allocator by calling std::allocator_traits<allocator_type>::select_on_container_copy_construction on the allocator of the container being copied. Move constructors obtain their instances of allo

void swap( basic_fstream& other ); (since C++11) Exchanges the state of the stream with those of other. This is done by calling basic_iostream<CharT, Traits>::swap(other) and rdbuf()->swap(other.rdbuf()). Parameters other - stream to exchange the state with Return value (none). Example See also operator= (C++11) moves the file stream (public member function) swap (C++11) swaps two basic_filebuf objects (public member function of std::basic_

Defined in header <locale> const char* scan_not (mask m, const char* beg, const char* end) const; (1) Locates the first character in the character array [beg, end) that does not satisfy the classification mask m, that is, the first character c such that table()[(unsigned char)c] & m would return false. If (unsigned char)c >= std::ctype<char>::table_size, then an implementation-defined value is substituted instead of table()[(unsigned char)c], possibly different

Usage noexcept operator noexcept specifier

A null-terminated wide string is a sequence of valid wide characters, ending with a null character. Functions Character classification Defined in header <cwctype> iswalnum checks if a wide character is alphanumeric (function) iswalpha checks if a wide character is alphabetic (function) iswlower checks if a wide character is lowercase (function) iswupper checks if a wide character is an uppercase character (function) iswdigit checks if a wide character i

A template parameter pack is a template parameter that accepts zero or more template arguments (non-types, types, or templates). A function parameter pack is a function parameter that accepts zero or more function arguments. A template with at least one parameter pack is called a variadic template. Syntax Template parameter pack (appears in a class template and in a function template parameter list). type ... Args(optional) (1) (since C++11) typename|class ... Args(optional) (2) (