C++ Design Tips and Tricks

C++ Design Tips and Tricks by Dr. Michael Whalen

C++ Design Tips Tip 1:

Learn Patterns

Someone has done what you are doing before:

For Example:

• Extracting information from a complex graph of classes (visitor)
• Creating a framework to notify observers when some data-of-interest changes (observer)

Design Patterns are a way of expressing these ideas that give you an abstract vocabulary for a complex idea

Good Book: “Design Patterns” by Gamma et. al GoF

C++ Design Tips Tip 2:

Learn Idioms

Idioms are easy ways of expressing certain universal concerns in your programming language of choice.

• Example: Resource Manager
• Example: Template Specialization
• Example: Enumeration Classes

Many found in books:

• “C++ Programming Language” – Stroustrup
• “C++ Common Knowledge – Dewherst
• “Essential C++” - ???

Idiom Example: Resource Acquisition is Initialization (RAII) Create class for managing resource Maps resource lifetime to object lifetime

Responsibilities:

• Ensure that resource is properly initialized in the constructor
• Ensures that the resource is properly freed in the destructor
• Ensures that resources are properly freed in the presence of exceptions.

C++ Design Tips Tip 3:

Design an Error-Handling Strategy

C++ Has Several Good Mechanisms for Error Handling. Strategy depends on application

My view:

• Asserts – use liberally for situations that should never occur
• Exceptions – use for situations that are very unlikely to occur
• For system applications, define additional facilities: logging, reporting, queuing, etc.

C++ Design Tips Tip 4:

The answer is not always Object-oriented.C++ allows a range of programming styles

Not every problem is OO, nor should it be.

Ex: A numeric algorithm, such as a sequnce of matrix transforms, is a function. This kind of function doesn’t make sense as a class member. Use namespaces to group related functions that do not belong in a class.