On Mon, 04 Jun 2012 20:57:11 +0200, simendsjo <simend...@gmail.com> wrote:
On Mon, 04 Jun 2012 20:36:14 +0200, Xinok <xi...@live.com> wrote:
The increment and decrement operators are highly dependent on operator
precedence and associativity. If the actions are performed in a
different order than the developer presumed, it could cause unexpected
behavior.
I had a simple idea to change the behavior of this operator. It works
for the postfix operators but not prefix. Take the following code:
size_t i = 5;
writeln(i--, i--, i--);
As of now, this writes "543". With my idea, instead it would write,
"555". Under the hood, the compiler would rewrite the code as:
size_t i = 5;
writeln(i, i, i);
--i;
--i;
--i;
It decrements the variable after the current statement. While not the
norm, this behavior is at least predictable. For non-static variables,
such as array elements, the compiler could store a temporary reference
to the variable so it can decrement it afterwards.
I'm not actually proposing we actually make this change. I simply
thought it was a nifty idea worth sharing.
If I ever saw a construct like that, I would certainly test how that
works, then rewrite it.
I wouldn't find it natural with the new behavior either. I would expect
"543" or "345".
How often do you come across code like that? I think it's an
anti-pattern, and shouldn't be encouraged even if it was easier to
understand.
Oh, and what should writeln(i++, ++i, ++i, i++) do?
It is messy whatever the logic implementation.
