Re: Questions about "mismatch"
On 22 Dez., 10:57, jacob navia wrote:
Why was end2 omitted?
That is the core of the discussion.
Even if you do not use the faster version, a difference test is just an
integer comparison, not likely to cost much.
Assuming std::mismatch accepted an end2 parameter you could write
if (distance(beg2,end2)<distance(beg1,end1)) {
signal an error
}
but that imposes an additional cost, of course. And this cost may be
O(n) depending on the kind of iterator.
Admittedly, the precondition about the second sequence's length could
be more explicit in the C++ standard. But it's rather self-
explanatory, if you apply common sense.
Anyhow, I couldn't care less about std::mismatch omitting an end2
parameter. As others have pointed out already, some vendors
(Microsoft, GNU) offer an "STL debug mode". So, you get to choose
between checking iterators/algorithms and fast iterators/algorithms.
I'm working in the high performance computing domain and I appreciate
how the C++ language/library design turned out.
Cheers!
SG