HP Integrity NonStop J-Series - Manual (Page 79)

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©Copyright 1996 Rogue Wave Software
Windows Clipboard and DDE Streambufs
In the previous section, you saw how the virtual streams facility abstracts the formatting of
items inserted into the stream. The disposition of the items inserted into the streams has also
been made abstract: it is set by the type of streambuf used.
Class streambuf is the underlying sequencing layer of the iostreams facility. It is responsible for
producing and consuming sequences of characters. Your compiler comes with several versions.
For example, class filebuf ultimately gets and puts its characters to a file. Class strstreambuf
gets and puts to memory-based character streams; you can think of it as the iostream equivalent
to ANSI-C's sprintf() function. Now Tools.h++ adds two Windows-based extensions:
Class RWCLIPstreambuf for getting and putting to the Windows Clipboard; ●
Class RWDDEstreambuf for getting and putting through the Windows Dynamic Data
Exchange (DDE) facility.
●
These classes take care of the details of allocating and reallocating memory from Windows as
buffers overflow and underflow. In the case of class
RWDDEstreambuf , the associated
DDEDATA header is also filled in for you. Any class that inherits from class ios can be used
with these streambufs, including the familiar
istream and ostream, as well as the Rogue Wave
virtual stream classes.
The result is that the same code that is used to store a complex structure to a conventional
disk-based file, for example, can also be used to transfer that structure through the DDE facility
to another application!