No. This is not what I meant. I absolutely agree that std::indirect is an improvement. My point is that when dealing with C++ code, now there is yet another way of doing the same thing. I will have to remember both ways, because people will still keep using the old way.

Ok, well, you have a point, in that you might see the old way of doing things and you might see the new way. This is, however, one of the detriments of the language's commitment to backwards-compatibility: Old-C++ code is (almost without fail) valid new-C++ code.

When you write new code, this is (mostly) not an issue; when you have to maintain old code, it is. Especially if the existing codebase is somewhat of a patchwork of code introduced at different points in time - pre-C++98, C++98, C++03, C++11 and so on. For this reason it is a saintly virtue to manage to unify the C++ "vernacular" used in a project, for better readability by newcomers and for facilitating uniform changes to the entire codebase later on.