30 Input/output library [input.output]

30.9 File-based streams [file.streams]

30.9.5 Class template basic_­fstream [fstream]

30.9.5.1 basic_­fstream constructors [fstream.cons]

basic_fstream();

Effects: Constructs an object of class basic_­fstream<charT, traits>, initializing the base class with basic_­iostream(&sb) and initializing sb with basic_­filebuf<charT, traits>().

explicit basic_fstream( const char* s, ios_base::openmode mode = ios_base::in | ios_base::out); explicit basic_fstream( const filesystem::path::value_type* s, ios_base::openmode mode = ios_base::in | ios_base::out); // wide systems only; see [fstream.syn]

Effects: Constructs an object of class basic_­fstream<charT, traits>, initializing the base class with basic_­iostream(&sb) and initializing sb with basic_­filebuf<charT, traits>(). Then calls rdbuf()->open(s, mode). If that function returns a null pointer, calls setstate(failbit).

explicit basic_fstream( const string& s, ios_base::openmode mode = ios_base::in | ios_base::out); explicit basic_fstream( const filesystem::path& s, ios_base::openmode mode = ios_base::in | ios_base::out);

Effects: The same as basic_­fstream(s.c_­str(), mode).

basic_fstream(basic_fstream&& rhs);

Effects: Move constructs from the rvalue rhs. This is accomplished by move constructing the base class, and the contained basic_­filebuf. Next basic_­istream<charT, traits>​::​set_­rdbuf(&sb) is called to install the contained basic_­filebuf.