Defined in header <locale> template< class charT > bool isupper( charT ch, const locale& loc ); Checks if the given character is classified as an uppercase alphabetic character by the given locale's std::ctype facet. Parameters ch - character loc - locale Return value Returns true if the character is classified as uppercase, false otherwise. Possible implementation template< class charT > bool isupper( charT ch, const std::locale&

Defined in header <cctype> int isupper( int ch ); Checks if the given character is an uppercase character as classified by the currently installed C locale. In the default "C" locale, isupper returns true only for the uppercase letters (ABCDEFGHIJKLMNOPQRSTUVWXYZ). If isupper returns true, it is guaranteed that iscntrl, isdigit, ispunct, and isspace return false for the same character in the same C locale. The behavior is undefined if the value of ch is not representable as

Defined in header <cmath> bool isunordered( float x, float y ); (1) (since C++11) bool isunordered( double x, double y ); (2) (since C++11) bool isunordered( long double x, long double y ); (3) (since C++11) bool isunordered( Arithmetic x, Arithmetic y ); (4) (since C++11) 1-3) Determines if the floating point numbers x and y are unordered, that is, one or both are NaN and thus cannot be meaningfully compared with each other. 4) A set of overloads or a f

char* str(); Returns the pointer to the beginning of the buffer, after freezing it. Effectively calls rdbuf()->str(). Parameters (none). Return value Pointer to the beginning of the buffer in the associated std::strsteambuf or NULL if no buffer is available. Example

strstreambuf* rdbuf() const; Returns a pointer to the associated std::strstreambuf, casting away its constness (despite the const qualifier on the member function). Parameters (none). Return value Pointer to the associated std::strsteambuf, with constness cast away. Example #include <strstream> int main() { const std::istrstream buf("example"); std::strstreambuf* ptr = buf.rdbuf(); }

explicit istrstream(const char* s); (1) explicit istrstream(char* s); (2) istrstream(const char* s, std::streamsize n); (3) istrstream(char* s, std::streamsize n); (4) Constructs new istrstream and its underlying std::strstreambuf. 1,2) Constructs the underlying std::strstreambuf by calling strstreambuf(s,0) and initializes the base class with the address of the strstreambuf. The behavior is undefined if s is not pointing at an element of a null-terminated array. 3,4

Defined in header <strstream> class istrstream : public std::istream (deprecated) The class istrstream implements input operations on array-backed streams. It essentially wraps a raw array I/O device implementation (std::strstreambuf) into the higher-level interface of std::basic_istream. The typical implementation of istrstream holds only one non-derived data member: an object of type std::strstreambuf. Notes istrstream has been deprecated since C++98, std::istringstrea

istream_iterator& operator++(); (1) istream_iterator operator++(int); (2) Reads a value from the underlying stream and stores it into the iterator object. The behavior is undefined if the iterator is end-of-stream iterator. Parameters (none). Return value 1) *this. 2) An istream_iterator that holds an unchanged value. Exceptions (none).

istream_iterator(); constexpr istream_iterator(); (1) (since C++11, only if T is literal type) istream_iterator( istream_type& stream ); (2) istream_iterator( const istream_iterator& other ) = default; (3) 1) Constructs the end-of-stream iterator. 2) Initializes the iterator and stores the address of stream in a data member. Optionally, performs the first read from the input stream to initialize the cached value data member (although it may be delayed until the fir

Defined in header <iterator> template< class T, class CharT = char, class Traits = std::char_traits<CharT>, class Distance = std::ptrdiff_t > class istream_iterator: public std::iterator<std::input_iterator_tag, T, Distance, const T*, const T&> (until C++17) template< class T, class CharT = char, class Traits = std::char_traits<CharT>, class