Hands-On Design Patterns with C++

Basic SFINAE

Let's start with a very basic problem—we have some general code that we want to call for all objects, except for built-in types. For integers and other built-in types, we have a specialized version of our code. This problem can be solved by explicitly listing all built-in types in a set of overloaded functions. And let's not forget raw pointers; they are also built-in types. And references. And constant pointers. With care, this approach can be made to work. But perhaps it would be simpler to somehow test whether our type is a class or not. We just need to find something that classes have, and built-in types do not. The obvious distinction is member pointers. Any function declaration that uses the member pointer syntax will fail ...