inline in definition and declaration

Question

During a recent peer review, another Software Engineer suggested that I state that the inline function is inline in the definition (outside of the

Answer 1

That sounds like two totally unrelated things. Putting inline at both the declaration in the class and the definition outside of the class is not needed. Putting it at one of the declarations is enough.

If you talk about adding inline in a .cpp file where a function is defined there, and that function is a public member, then you should not do that. People who call inline functions must have their definitions visible to them. The C++ Standard requires that.