But another minor thing that I don't understand is why the template parameters of the transform_iterator and the parameters of its constructor are in the different order. If I were the author, I would feel keeping them in the same order be more natural and more straightforward. Perhaps letting Function be the 1st template parameter make it clearer the behavior of the class? :-) If this is a too stupid question, just ignore. :-) Thanks. B/Rgds Max ----- Original Message ----- From: Steven Watanabe To: boost-users@lists.boost.org Subject: Re: [Boost-users] [iterator] transform_iterator Date: 2008-12-25 00:47:36 AMDG Max wrote:
I just came across transform_iterator and found it a useful generic tool. But is it possible for it to go further to make the following code get compiled and run as expected?
No.
struct A { int i_; A() : i_(0) {} explicit A(int i) : i_(i) {} };
const int N = 5; A a_list[N] = { A(-3), A(1), A(3), A(2), A(-4) };
typedef boost::function fn_t;
// sorting a_list according to the elements' i_ member std::stable_sort(boost::make_transform_iterator(a_list, fn_t(boost::bind(&A::i_, _1))), boost::make_transform_iterator(a_list+N, fn_t(boost::bind(&A::i_, _1))), std::less());
stable_sort assumes that the sort keys are the same as the objects that it is moving around. In Christ, Steven Watanabe ------------------------------------------------------------------- 新浪空间——与朋友开心分享网络新生活！(http://space.sina.com.cn/ ) ------------------------------------------------------------------- 新浪空间——与朋友开心分享网络新生活！(http://space.sina.com.cn/ )