[kazinator]

Yes, return can be a function. Torvalds hasn't heard of continuations, obviously, where we "return" from a function by invoking a continuation.

We can justify writing return (expr); using the same arguments that justify the sizeof (expr) convention.

The thing is that in C, return isn't a function; there are no continuations.

Similarly, sizeof is an operator, which doesn't reduce its argument expression to a value.

If we are going to make coding conventions based on pretending that C is a different language in which sizeof is a function, then pretending return is a function is also fair game.

[hueving]

He is talking about C. Continuations are irrelevant.

[kazinator]

That point is clearly made in the comment you're replying to, with the additional point that if we are talking about C, then sizeof is an operator, not a function. It doesn't require parentheses, except when its operand is a type expression. No well-considered coding convention requires superfluous parentheses with sizeof, and there are good reasons to ban them.

We should prefer code like:

   type *ptr = malloc(sizeof *ptr);  /* no parens */

to

   type *ptr = malloc(sizeof (type));

In general it's often better to base sizeof on an ordinary expression rather than a type expression.

If we don't use superfluous parentheses on sizeof, we can then look for sizeof followed by an open parenthesis to look for code where sizeof is applied to a type expression.

  sizeof (type)

means "produce me a size_t value based on some arbitary type, without checking that it's related to anything in the surrounding code". It can be as dangerous as a (type) cast.

[newuser88273]

Scheme has come up with the idea of pretending that an undelimited contination is a function, which is somewhat true-ish... in the degenerate sense of a function with empty domain.

This is fine for Scheme, which is an expression language, so every method of invoking a continuation would, syntactically, be an expression anyway.

In C, which has statements, making return look like an expression is somewhat pointless. It doesn't matter whether C "has" continuations (and it arguably has) or not.

[anonbanker]

Why shouldn't return be considered a function?