On Thursday, 10 January 2013 at 20:24:02 UTC, Charles Hixson wrote:
> On 01/10/2013 08:41 AM, Ali Çehreli wrote:
>> On 01/09/2013 04:14 PM, Charles Hixson wrote:
>>> Would the following code:
>>> for (int i = 1; i < di.count; i++)
>>> { assert (node.di.entry[i - 1].key < node.di.entry[i].key); }
>>>
>>> be optimized away if compiled under -release?
>>
>> It looks like you can use std.algorithm.isSorted instead:
>>
>> http://dlang.org/phobos/std_algorithm.html#isSorted
>>
>> assert(isSorted(di));
>>
>> Or perhaps:
>>
>> assert(isSorted(node.di.entry[0 .. di.count]));
>>
>> That code will disappear in release mode.
>>
>> Additionally, if the O(N) complexity of that check is not acceptable
>> even in non-release mode there is std.range.assumeSorted:
>>
>> http://dlang.org/phobos/std_range.html#.assumeSorted
>>
>> assumeSorted makes very few comparisons so it may miss occasional sort
>> issues. Also, it is not really for checking but more for range
>> algorithms that require or work better with a sorted range.
>>
>> Ali
> OTOH, if :
> version(assert)
> {...}
> works as suggested by monarch_dodra above, that will allow me to avoid the problem.

Well, you check if something is sorted by hand, if the code to check it already exists?

> Unfortunately, entry is also a struct.  key isn't its only member.  If there's some other reason to define a opCmp on entry, that would be a good approach.

I'm not entirely sure what you mean by that. The fact that it is a struct should pose no problem.

As for whether or you need to define opCmp, keep in mind that "isSorted" (and *anything else* related to sorted in general) take a "less" paramter

http://dlang.org/phobos/std_algorithm.html#isSorted

So you can write an external "foo" function, that takes 2 entries, and returns the "lowest" one (by any custom ordering), and then call:

isSorted!foo(myStuff)