On Fri, 12 Aug 2011 19:19:09 +0200, Marco Leise <[email protected]> wrote:
Am 12.08.2011, 17:48 Uhr, schrieb Simen Kjaeraas
<[email protected]>:
On Fri, 12 Aug 2011 14:55:26 +0200, Marco Leise <[email protected]>
wrote:
Am 12.08.2011, 12:22 Uhr, schrieb kennytm <[email protected]>:
Don <[email protected]> wrote:
I've had a look at a dozen or so of these, and they were all real. I
didn't see any which require a cast to "make the compiler shut up".
That's pretty impressive. In C++ I find that such messages are nearly
always false positives.
The one case where it's a bit annoying is this:
int [] x = new int[6]; // or x = some array literal.
for (int i = 0; i < x.length; ++i) {...}
Here is a suggestion for how we could eliminate such false positives.
http://d.puremagic.com/issues/show_bug.cgi?id=6478
Doesn't this require flow analysis? And the type of index 'i' should
be
'size_t' anyway.
I think I once shot myself in the foot with this when I used 'auto'
for 'i' and the code wouldn't compile on x86_64, because I assigned
the variable to an int or uint later on in the loop. You just have to
be aware that this is an unsigned integer of machine word length. So I
agree with kennytm on this.
Just remember that reverse loops are written like this:
for (size_t i = x.length; i-- > 0; ) {...}
I like using the long arrow operator for this:
i --> 0 // i goes to 0
This way it is actually fun to cripple the for loop, yay. Still if
people started to argue that it is a bad idea to modify variables in the
condition I'd silently agree. So a look at "foreach_reverse (i;
0..x.length) {...}" might be worth it. I guess after a while I will get
used to it. It even reminds me of the Pascal "for"-syntax a bit, which
is "for i := 0 to 9 do ...". It has no receipt for the reverse
zero-length array loop though as far as I know.
Pascal has downto:
for i := 9 downto 0 do ...
--
Simen
