Input and output together: class `iostream'
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If you need to use the same stream for input and output, you can use
an object of the class `iostream', which is derived from _both_
`istream' and `ostream'.
The constructors for `iostream' behave just like the constructors
for `istream'.
- Constructor: iostream::iostream ()
When used without arguments, the `iostream' constructor simply
allocates a new `ios' object, and initializes the input counter
(the value reported by `istream::gcount') to `0'.
- Constructor: iostream::iostream (streambuf* SB [, ostream* TIE])
You can also call a constructor with one or two arguments. The
first argument SB is a `streambuf*'; if you supply this pointer,
the constructor uses that `streambuf' for input and output.
You can use the optional second argument TIE (an `ostream*') to
specify a related output stream as the initial value for
`ios::tie'.
As for `ostream' and `istream', `iostream' simply uses the `ios'
destructor. However, an `iostream' is not deleted by its destructor.
You can use all the `istream', `ostream', and `ios' methods with an
`iostream' object.