08_IO_Streams.md

8. I/O Streams

8.2 Output

• <ostream>
• << to write to a stream object
• cout is stdout, cerr is stderr
• Chaining << is possible: cout << a << b;

8.3 Input

• <istream>
• >> to write to a stream object
• cin is stdin. Whitespace is stripped by default
• getline to read entire lines

8.4 I/O State

• stream objects hold state
• Testing an object (in an if or for) returns results depending on the state
• This allows us to iterate over streams elegantly: while(is >> i) { … }

8.5 I/O of User-Defined Types

• We can overload << and >> to work with user-defined types
• There are methods for setting the state of a stream (failbit, badbit)

8.6 Formating

• Manipulators can be used for formatting
• cout << hex << 16;
• To manipulate the entire stream, there are special methods, e.g. cout.precision(5)

8.7 File Streams

• Similary, there are streams for files. Nothing surprising here

8.8 String Streams

• <sstream>, stringstream for streaming strings
• (Note: This seems to be just for convenience, not performance)
• template<typename T=string> for setting a default