I/O Manipulators with Parameters - 4

• Useage:

os << SetWidth(8) << x;

• Sequence of events:
1. temporary SetWidth(8) object created (call it "temp")
2. operator<< called with arguments (os, temp)
3. temp(os) called, that is:
4. temp.operator() called with argument os
5. os.width(8) called
6. object temp goes out of scope
7. operator<< returns reference to os for application of os << x
• Can also be applied to input:

is >> SetWidth(20) >> y;