problem calling function

I have a function:

Code:

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list<Coord>::iterator partition(list<Coord>& mList, list<Coord>::iterator it){

    double x = it->get_x();
    double y = it->get_y();

    double dist = distance(x,y)/3;

    return it;
}

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I'm getting this error when it reaches the call to the distance function:

Code:

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/usr/include/c++/4.1.3/bits/stl_iterator_base_types.h: In instantiation of 'std::iterator_traits<double>’:
main3.cpp:205:  instantiated from here
/usr/include/c++/4.1.3/bits/stl_iterator_base_types.h:129: error: ‘double’ is not a class, struct, or union type

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but if I just replace the function call with the distance formula itself, it works.

any ideas??

distance is a function from <iterator> that returns the distance between two iterators, and I think that might be causing problems. Sorry.:( Maybe call your distance function something else? We can at least see if that's what's causing problems.

Quote:

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Originally Posted by tabstop

distance is a function from <iterator> that returns the distance between two iterators, and I think that might be causing problems. Sorry.:( Maybe call your distance function something else? We can at least see if that's what's causing problems.

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Yeah, that was it. Amazing how I've never ran into that problem before using the name distance to denote a distance function. Does this problem arise only if you're using <iterator> or <list> or something of the sort?

The culprit is really the line

Code:

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using namespace std;

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since normally you would have to use std::distance for the version in <iterator>. But yeah, if you don't include that header, you also won't import the function name. (Of course, then you can't use iterators, so that's not really a solution here.

Not including the header is too risky, because another header may well include it.