[leni536]

> C++ could adopt the UFCS universal-function-call feature of D-language that allows any ordinary free function to be called as if they were methods, without any special kind of type annotation.

It really couldn't. It would be a breaking change.

[gpderetta]

what would it break? It litterally was proposed by an extension, with support from Stroustrup.

IIRC Stroustrup regrets using . for member function calls (as opposed to just some syntactic sugar for any function call)

[leni536]

The way it was worded in the GP comment would change name lookup in existing well-formed programs, making them fail to compile, or compile differently.

I'm not familiar with Stroustrup's proposal, but I doubt that he proposed it without some opt-in annotation.