On Wed, Nov 26, 2008 at 09:15, Thorsten Ottosen <thorsten.ottosen@dezide.com> wrote:
Giovanni Piero Deretta skrev:
On Wed, Nov 26, 2008 at 4:46 AM, Scott McMurray <me22.ca+boost@gmail.com> wrote:
[...]
[ i think you want to change all node_iter to nonsingular_default ]
Yes, dumb copy-paste mistake on my part.
I do not think you can even copy a singular iterator (and at least libstdc++ will assert in debug mode),
Right. you can't even copy a singular iterator (not portably, at least).
Another good point. I think this works, as the iterator_adaptor's copy ctr is never called: template <class Iter> class nonsingular_default : public boost::iterator_adaptor< nonsingular_default<Value> // Derived , Iter // Base > { private: bool is_default_constructed; public: nonsingular_default() : nonsingular_default::iterator_adaptor_(), is_default_constructed(true) {} nonsingular_default(Iter const &i) : nonsingular_default::iterator_adaptor_(i), is_default_constructed(false) {} nonsingular_default(nonsingular_default const &i) { *this = i; } nonsingular_default &operator=(nonsingular_default const &i) { is_default_constructed = i.is_default_constructed; if (!is_default_constructed) { base_reference() = i.base(); } } private: friend class boost::iterator_core_access; bool equal(nonsingular_default const &i) { if (is_default_constructed && i.is_default_constructed) { return true; } if (!is_default_constructed && !i.is_default_constructed) { return base == i.base(); } return false; } };