SFINAE

SFINAE, or Substitution Failure Is Not An Error, is one of those concepts in C++ that often leaves developers scratching their heads at first. But once you wrap your mind around it, it opens up a whole new world of template metaprogramming possibilities.

If you’ve ever tried to write a template that behaves differently depending on the types it’s given, you’ve likely encountered SFINAE, even if you didn’t know it at the time.

Understanding SFINAE allows you to write more flexible and robust code by enabling you to conditionally enable or disable template overloads based on the characteristics of the types passed in. This is the key to crafting templates that can adapt to varying situations without breaking compilation.