Templates and Genericity

64. Blend static and dynamic polymorphism judiciously.

So much more than a mere sum of parts: Static and dynamic polymorphism are complementary. Understand their tradeoffs, use each for what it's best at, and mix them to get the best of both worlds.

65. Customize intentionally and explicitly.

Intentional is better than accidental, and explicit is better than implicit: When writing a template, provide points of customization knowingly and correctly, and document them clearly. When using a template, know how the template intends for you to customize it for use with your type, and customize it appropriately.

66. Don't specialize function templates.

Specialization is good only when it can be done correctly: When extending someone else's function template (including std::swap), avoid trying to write a specialization; instead, write an overload of the function template, and put it in the namespace of the type(s) the overload is designed to be used for. (SeeItem 57.) When you write your own function template, avoid encouraging direct specialization of the function template itself.

67. Don't write unintentionally nongeneric code.

Commit to abstractions, not to details: Use the most generic and abstract means to implement a piece of functionality.