Thinking in C++ Vol 2 - Practical Programming
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Output stream formatting

The goal of the iostreams design is to allow you to easily move and/or format characters. It certainly wouldn t be useful if you couldn t do most of the formatting provided by C s printf( ) family of functions. In this section, you ll learn all the output formatting functions that are available for iostreams, so you can format your bytes the way you want them.

The formatting functions in iostreams can be somewhat confusing at first because there s often more than one way to control the formatting: through both member functions and manipulators. To further confuse things, a generic member function sets state flags to control formatting, such as left or right justification, to use uppercase letters for hex notation, to always use a decimal point for floating-point values, and so on. On the other hand, separate member functions set and read values for the fill character, the field width, and the precision.

In an attempt to clarify all this, we ll first examine the internal formatting data of an iostream, along with the member functions that can modify that data. (Everything can be controlled through the member functions, if desired.) We ll cover the manipulators separately.

Thinking in C++ Vol 2 - Practical Programming
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