on Sat May 12 2007, Andrey Semashev <andysem-AT-mail.ru> wrote:
Hello David,
<please avoid overquoting>
I apologize for returning to this, but as I'm reading the docs and looking at my use cases I have before me I don't see how would I elide is_const_iterator when using iterator_adaptor. Suppose this:
template< typename ValueT > class MyList { public: typedef ValueT value_type;
// etc. all other common typedefs except iterators
private: struct MyNode { ValueT value; int m_SomeOtherData; }; typedef std::list< MyNode > underlying_container;
template< typename > class MyIterator;
public: typedef MyIterator< typename underlying_container::iterator > iterator;
typedef MyIterator< typename underlying_container::const_iterator > const_iterator;
private: template< typename ItT > class MyIterator : public iterator_adaptor< MyIterator< ItT >, ItT, value_type, // I have to substitute value type
No, just leave it out. The default works.
use_default, // Category fits well ??? // What should I write for reference type? // I've provided value type, so value_type& // is not valid when ItT is const_iterator
Just leave it out. The default works.
> { typedef typename iterator_adaptor< ... >::reference reference;
reference dereference() { return this->base()->value; } }; };
So, once again I have to detect ItT constness and form up the correct reference type for the iterator_adaptor. Am I missing something?
...unless I'm missing something. -- Dave Abrahams Boost Consulting http://www.boost-consulting.com Don't Miss BoostCon 2007! ==> http://www.boostcon.com