Why is there no clamp function in math.h

`math.h` goes to the trouble of providing `min` and `max`, but not a clamp function. I would have thought that as they are all usually similar implementation-wise they would all appear in the same library. Is there any particular reason that `math.h` does not feature a clamp function|macro? Is it that the creators of `math.h` did not deem it necessary or did they just not think about it? EDIT: It seems people are missing the point here. I'm not asking why didn't they add clamp because I'm lazy and don't like writing a new clamp - quite the opposite, I hardly ever use it (though admittedly I use it more than I use some of the standard libraries). What I'm asking is "does anyone know of any reason why the c++ standardisation authorities or creators or whoever chose not to include a clamp function in `math.h`?". I am by no means complaining that it is not in `math.h`, I am merely asking "is there a good reason it isn't there?". EDIT: I am explicitly not asking how to write a `clamp()` function.