> I'm not sure I agree that C++ Templates + Concepts are really equivalent to Lisp macros. I think I said as much in my comment. > This seems more akin to Com

> I'm not sure I agree that C++ Templates + Concepts are really equivalent to Lisp macros. I think I said as much in my comment. > This seems more akin to Common Lisp's defgeneric and defmethod Except that Templates are statically dispatched and type-checked. But also one can perform meaningful compile-time computation with them - I have used this in anger to implement stencils and iteration logic for partial differential equation solvers in 1-3 dimensions so I can say from experience that it is not a mere curiosity. And I don't think that CLOS really has any analog for the techniques used to implement std::tuple. > But macros let you do something else entirely. You can create entirely new syntactic structures, or modify existing functions (see Norvig's PAIP, chapter 9, where macros are used to memoize recursive functions), or any number of other things. I think the thrust of my comment is that Lisp programmers identify this type-blind AST-mapping functionality as the core of "a Macro System," while users of other languages (with more syntax to begin with) see this as somewhat secondary to the goal of type-checked compile-time computation.