Obtain the source code for the PFArrayD class and the demonstration program from Displays...

Obtain the source code for the PFArrayD class and the demonstration program from Displays 11.10, 10.11, and 10.12. Modify this program to use namespaces and separate compilation. Put the class definition and other function declarations Programming Projects 517 in one file. Place the implementations in a separate file. Distribute the namespace definition across the two files. Place the demonstration program in a third file. To provide access to names in namespaces, you may use local using declarations such as

or use local using directives such as

inside a block, or qualify names using the names of namespaces, such as std::cout.

You may not use global namespace directives such as the following which are not in a block and apply to the entire file: