C++ supports this sort of thing directly. It says something about C++ takeup that anyone would bother adding this kludge to C. Many people are scared of C++. The language has become incredibly complex.
C++ templates are Turing-complete. You can do arbitrary computation at compile time. Once this was discovered, ever-fancier templates became a basic part of C++. (Take a look at the huge templates that implement "max" and "min".) Then the C++ standards committee went off into template la-la land, focusing on adding features to make the template system more powerful. After a decade of this, many standard templates are now at the "you are not supposed to understand this" level.
This has scared people off of C++, which is why there's still much work in standard C. So now we're seeing features added to C to solve specific problems, but without an architecture.
"Defer" is troublesome, because dealing with errors in deferred statements is hard. C++ has the same problem with destructors. A "with" clause, which LISP introduce as "with-open-file" and Python also supports, is a better way to do this. Python's combination of "with" and exception handling can handle an error when closing out a resource, and get all the nested resources closed out properly. Few other languages even try to get that right.
Not touching on the rest of what you said, but what's so bad about min? Apart from some internal clang stuff, like odd names and macros, it looks okay - I can see what the function is doing.
Because a macro in C/C++ is just text expansion, the given implementation will evaluate its arguments more than once, which will not be obvious at the "call" site and could have unintended consequences if the expressions have side-effects.
Is there another way to do it as a macro that avoids this? How do you have temporary variables potentially in the middle of a larger expression, e.g. if (min(a,b) == 3) {...}
I think I just see it as different niches. C++ only adds to the code after a certain amount of complexity because there is so much magic its hard to manually translate to assembly in your head (at times). I certainly don't know much about c++ >03; the additions have been.... Probably not worth using over c for the massive probability and ability to contribute easily for small tools.
C++ templates are Turing-complete. You can do arbitrary computation at compile time. Once this was discovered, ever-fancier templates became a basic part of C++. (Take a look at the huge templates that implement "max" and "min".) Then the C++ standards committee went off into template la-la land, focusing on adding features to make the template system more powerful. After a decade of this, many standard templates are now at the "you are not supposed to understand this" level.
This has scared people off of C++, which is why there's still much work in standard C. So now we're seeing features added to C to solve specific problems, but without an architecture.
"Defer" is troublesome, because dealing with errors in deferred statements is hard. C++ has the same problem with destructors. A "with" clause, which LISP introduce as "with-open-file" and Python also supports, is a better way to do this. Python's combination of "with" and exception handling can handle an error when closing out a resource, and get all the nested resources closed out properly. Few other languages even try to get that right.