[now]

Out of interest, what breaking changes have been introduced to C in C99 and C11 (I’m assuming we’re using C89 as a baseline) beyond changes in corner cases in tokenization due to the introduction of “//” comments (and perhaps the removal of gets)?

[steveklabnik]

The removal of gets is what I was thinking of.

FWIW, I think that's the right thing to do. My point is just that the OP has completely unrealistic expectations of how actual programming languages work. What actually matters is, how much pain do you feel when upgrading to a new version of the language? The removal of gets violates the parent's "even once is one time too many", even though in practice, it's a complete non-issue.

[Annatar]

The removal of gets is what I was thinking of.

gets(3C) is a standard C library function; it has nothing whatsoever to do with C the language. Proof:

  Standard C Library Functions                             gets(3C)

  NAME
       gets, fgets - get a string from a stream

  SYNOPSIS
       #include <stdio.h>

       char *gets(char *s);

       char *fgets(char *s, int n, FILE *stream);
 

Rust is targeted at people who write system code in C (me). But how the hell are you going to appeal to my demographic group, when you don't distinguish between libc and C the programming language?

What actually matters is, how much pain do you feel when upgrading to a new version of the language?

And this is where you (plural) err: take the illumos source code, for example. Take the GNU/Linux source code! No, take the OpenBSD or FreeBSD source code. How many lines of C code does any of those code bases have? You expect us to rip it all out and replace it with a different language. What is our cost of replacement?

That's the burning issue! And even that's ignoring the fact that the syntax of Rust and the concepts like borrowing are insane, and map to nothing in the experience of your target demographic, the system programmers.