29 Input/output library [input.output]

29.9 File-based streams [file.streams]

29.9.3 Class template basic_­ifstream [ifstream]

29.9.3.1 General [ifstream.general]

namespace std { template<class charT, class traits = char_traits<charT>> class basic_ifstream : public basic_istream<charT, traits> { public: using char_type = charT; using int_type = typename traits::int_type; using pos_type = typename traits::pos_type; using off_type = typename traits::off_type; using traits_type = traits; // [ifstream.cons], constructors basic_ifstream(); explicit basic_ifstream(const char* s, ios_base::openmode mode = ios_base::in); explicit basic_ifstream(const filesystem::path::value_type* s, ios_base::openmode mode = ios_base::in);// wide systems only; see [fstream.syn] explicit basic_ifstream(const string& s, ios_base::openmode mode = ios_base::in); explicit basic_ifstream(const filesystem::path& s, ios_base::openmode mode = ios_base::in); basic_ifstream(const basic_ifstream&) = delete; basic_ifstream(basic_ifstream&& rhs); // [ifstream.assign], assign and swap basic_ifstream& operator=(const basic_ifstream&) = delete; basic_ifstream& operator=(basic_ifstream&& rhs); void swap(basic_ifstream& rhs); // [ifstream.members], members basic_filebuf<charT, traits>* rdbuf() const; bool is_open() const; void open(const char* s, ios_base::openmode mode = ios_base::in); void open(const filesystem::path::value_type* s, ios_base::openmode mode = ios_base::in); // wide systems only; see [fstream.syn] void open(const string& s, ios_base::openmode mode = ios_base::in); void open(const filesystem::path& s, ios_base::openmode mode = ios_base::in); void close(); private: basic_filebuf<charT, traits> sb; // exposition only }; }
The class basic_­ifstream<charT, traits> supports reading from named files.
It uses a basic_­filebuf<​charT, traits> object to control the associated sequence.
For the sake of exposition, the maintained data is presented here as: