Wave/flex_string with VC7.0 + dinkumware (new problem)
I reported that VC7 uses the correct implementation of reverse_iterator, and that this can be detected via BOOST_NO_STD_ITERATOR. Although this compiles, you cannot use reverse iterators. The problem is that the iterator is of the form (const) T *, and this fails because there is not a correct implementation of iterator_traits (due to a lack of partial template specialization) that *is* detected by BOOST_NO_STD_ITERATOR_TRAITS. The solution would therefore be to - in this case - provide an iterator wrapper around a standard pointer so it has the correct Iter::value_type, etc definitions. Is there an iterator_adaptor that provides this within boost? If not, should there be one? I am looking into this and will commit the solution to my iterator_adaptor-style implementation (sandbox/boost/fixed_string/detail/basic_string_impl.hpp). NOTE: If you want to add any of my modifications to the Wave flex_string implementation, feel free, but be warned that I haven't run full tests on it yet and thus there might be bugs in it (especially the pod_xxx --> traits_type::xxx, since these functions have different parameters). Regards, Reece _________________________________________________________________ It's fast, it's easy and it's free. Get MSN Messenger today! http://www.msn.co.uk/messenger
Reece Dunn wrote:
I reported that VC7 uses the correct implementation of reverse_iterator, and that this can be detected via BOOST_NO_STD_ITERATOR. Although this compiles, you cannot use reverse iterators.
The problem is that the iterator is of the form (const) T *, and this fails because there is not a correct implementation of iterator_traits (due to a lack of partial template specialization) that *is* detected by BOOST_NO_STD_ITERATOR_TRAITS.
The solution would therefore be to - in this case - provide an iterator wrapper around a standard pointer so it has the correct Iter::value_type, etc definitions. Is there an iterator_adaptor that provides this within boost? If not, should there be one? I am looking into this and will commit the solution to my iterator_adaptor-style implementation (sandbox/boost/fixed_string/detail/basic_string_impl.hpp).
NOTE: If you want to add any of my modifications to the Wave flex_string implementation, feel free, but be warned that I haven't run full tests on it yet and thus there might be bugs in it (especially the pod_xxx --> traits_type::xxx, since these functions have different parameters).
Thanks again for pointing that out. I'll have a look at it next week, when I'm back home. Is this problem specific for VC7 or does it occur on the VC7.1 platform also? If it's specific, then I would some need from somebody to fix this, because I don't have it handy to reproduce the problem. Could you provide a fix for Wave then? Regards Hartmut
"Reece Dunn" <msclrhd@hotmail.com> writes:
I reported that VC7 uses the correct implementation of reverse_iterator, and that this can be detected via BOOST_NO_STD_ITERATOR. Although this compiles, you cannot use reverse iterators.
Just use boost::reverse_iterator instead. It works better anyway.
The problem is that the iterator is of the form (const) T *, and this fails because there is not a correct implementation of iterator_traits (due to a lack of partial template specialization) that *is* detected by BOOST_NO_STD_ITERATOR_TRAITS.
Just use boost::detail::iterator_traits instead (from boost/detail/iterator.hpp); it works better anyway.
The solution would therefore be to - in this case - provide an iterator wrapper around a standard pointer so it has the correct Iter::value_type, etc definitions.
Ick.
Is there an iterator_adaptor that provides this within boost? If not, should there be one? I am looking into this and will commit the solution to my iterator_adaptor-style implementation (sandbox/boost/fixed_string/detail/basic_string_impl.hpp).
Sounds like a hard way to go, but it's easy to build. // untested template <class T> struct non_pointer_iterator : iterator_adaptor<non_pointer_iterator<T>, T> { typedef iterator_adaptor<non_pointer_iterator<T>, T> super; non_pointer_iterator() {} non_pointer_iterator(T x) : super(x) {} template <class U> node_iter( non_pointer_iterator<U> const& other , typename boost::enable_if< boost::is_convertible<U,T> , char >::type = 0 ) : super_t(other.base()) {} }; -- Dave Abrahams Boost Consulting http://www.boost-consulting.com
participants (3)
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David Abrahams -
Hartmut Kaiser -
Reece Dunn