[mojuba]

According to the OP tweet though, `foo()` is now a function that takes no arguments.

[zx2c4]

Here's the document for that change: http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2841.htm

> In this proposal, a function declarator without a parameter list declares a prototype for a function that takes no parameters (like it does in C++).

And it seems like gcc implements this under -std=c2x now:

    zx2c4@thinkpad /tmp $ cat a.c
    int blah()
    {
            return 7;
    }
    
    int main(int argc, char *argv[])
    {
            return blah(argc);
    }
    zx2c4@thinkpad /tmp $ gcc -std=c17 a.c
    zx2c4@thinkpad /tmp $ gcc -std=c2x a.c
    a.c: In function ‘main’:
    a.c:8:16: error: too many arguments to function ‘blah’
        8 |         return blah(argc);
          |                ^~~~
    a.c:1:5: note: declared here
        1 | int blah()
          |     ^~~~

[leetrout]

Agree the tweet makes it seem the behavior is changing.

Edit: parent is correct it IS changing

> We could make this change because foo() decls and definitions had been deprecated since C89/99, longer than I've been alive.

> Implementations will likely warn on foo() decls for a while, and error if someone calls it with foo(too, many, args);.

https://mobile.twitter.com/__phantomderp/status/149481259506...

[jesprenj]

Wouldn't int foo(void) be a function that takes no arguments and int foo() a function that takes an unknown number of arguments?

[suprjami]

Yes, that's the problem.

[duskwuff]

Which is much more consistent, IMO.

int foo(int, int) is a function taking two arguments. int foo(int) is a function taking one argument. int foo() ought to mean a function taking no arguments, not a function with an unspecified number of arguments!

[suprjami]

That's a different thing. That's implied `foo(void)`.

[messe]

It WAS a different thing. That's changing in C23.