The extended framework adds memory streams to the binary, narrow character, Unicode character, and wide character stream families. These streams write data to memory. Only output streams are included because the performance problems occur only during output operations. A new handle class for each stream family is required in order to access the content of the memory written by the memory output stream.

The extended framework is built on top of the common framework and is composed of a handle class, an abstract body class, and a concrete class for each stream family, as shown in Figure 4.