The GNU C++ Iostream Library

3.1.3: Changing stream properties using manipulators

For convenience, manipulators provide a way to change certain properties of streams, or otherwise affect them, in the middle of expressions involving `<<' or `>>'. For example, you might write

cout << "|" << setfill('*') << setw(5) << 234 << "|";

to produce `|**234|' as output.

Manipulator:  ws

Skip whitespace.

Manipulator:  flush

Flush an output stream. For example, `cout << ... <<flush;' has the same effect as `cout << ...; cout.flush();'.

Manipulator:  endl

Write an end of line character `\n', then flushes the output stream.

Manipulator:  ends

Write `\0' (the string terminator character).

Manipulator:  setprecision (int signif)

You can change the value of ios::precision in `<<' expressions with the manipulator `setprecision(signif)'; for example,

cout << setprecision(2) << 4.567;

prints `4.6'. Requires #include <iomanip.h>.

Manipulator:  setw (int n)

You can change the value of ios::width in `<<' expressions with the manipulator `setw(n)'; for example,

cout << setw(5) << 234;

prints ` 234' with two leading blanks. Requires #include <iomanip.h>.

Manipulator:  setbase (int base)

Where base is one of 10 (decimal), 8 (octal), or 16 (hexadecimal), change the base value for numeric representations. Requires #include <iomanip.h>.

Manipulator:  dec

Select decimal base; equivalent to `setbase(10)'.

Manipulator:  hex

Select hexadecimal base; equivalent to `setbase(16)'.

Manipulator:  oct

Select octal base; equivalent to `setbase(8)'.

Manipulator:  setfill (char padding)

Set the padding character, in the same way as ios::fill. Requires #include <iomanip.h>.