Examples

There are several instances in which you can replace run-time checks with compile-time checks.

Example 1: Compile-time Boolean conditions. If you are testing for compile-time Boolean conditions such as sizeof(int) >= 8, use static assertions instead of run-time tests. (But see also Item 91.)

Example 2: Compile-time polymorphism. Consider replacing run-time polymorphism (virtual functions) with compile-time polymorphism (templates) when defining generic functions or types. The latter yields code that is better checked statically. (See also Item 64.)

Example 3: Enums. Consider defining enums (or, better yet, full-fledged types) when you need to express symbolic constants or restricted integral values.

Example 4: Downcasting. If you frequently use dynamic_cast (or, worse, an unchecked static_cast) to perform downcasting, it can be a sign that your base classes offer too little functionality. Consider redesigning your interfaces so that your program can express computation in terms of the base class.