Hey all,
I have a list of classes, and two iterators, it_cur and it_nxt. It_cur points to some element, and I need it_nxt to point to the element after it_cur. Is there any simple built in way to do this? If not, would using the following function be alright?
Or maybe just it_nxt = it_cur + sizeof(TheClass)?Code:list<TheClass>::iterator getNext(list<TheClass>::iterator it_cur) { return ++it_cur; }
Cheers,
Gabe
>> If not, would using the following function be alright?
Yes, that would work fine (though you may want to check that it_cur != end( )).
>> Or maybe just it_nxt = it_cur + sizeof(TheClass)?
Definitly *not*. That would increment the iterator sizeof(TheClass) times. It works just like normal pointer arithematic, actually.
Code:#include <cmath> #include <complex> bool euler_flip(bool value) { return std::pow ( std::complex<float>(std::exp(1.0)), std::complex<float>(0, 1) * std::complex<float>(std::atan(1.0) *(1 << (value + 2))) ).real() < 0; }
One way would be:Originally Posted by G4B3
But once you have such an iterator pair, you could also write:Code:it_nxt = it_cur; ++it_nxt;
Code:it_cur = it_nxt++;No. If the iterators are random access iterators, that would likely set it_nxt to a far more advanced position than desired. If not, that would likely result in a compile error since operator+ is not usually defined for say, the bidirectional iterators of a std::list (you would use std::advance() instead).
Last edited by laserlight; 05-27-2009 at 07:25 AM.
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advance() was the function I was looking for. Thanks, I completely missed it in the reference.
Cheers,
Gabe
PS.: Sorry about the + sizeof(TheClass) thing, I mixed things up in my head and treated a list as an array.
