In C++, input/output is provided through the library.
IO library facilities:
- istream (input stream) type, which supports input operations
- ostream (output stream) type, which provides output operations
- cin an istream object that reads the standard input.
- cout an ostream object that writes to the standard output
- cerr an ostream object that writes to the standard error. cerr is usually used for program error messages.
- operator », which is used to read input from an istream object
- operator «, which is used to write output to an ostream object
- getline function, which takes a reference to an istream and a reference to a string and reads a word from the istream into the string
No Copy or Assign for IO Objects
ofstream out1, out2;
out1 = out2; // error: cannot assign stream objects
// print function: parameter is copied
out2 = print(out2); // error: cannot copy stream objects