[Boost-users] [Iterator] const and an iterator's value_type

From: Daniel Mitchell (danmitchell_at_[hidden])
Date: 2006-07-13 12:10:05

In the documentation of iterator_facade it is stated that:

"The C++ standard requires an iterator's value_type not be const-qualified, so 
iterator_facade strips the const from its Value parameter in order to produce 
the iterator's value_type. Making the Value argument const provides a useful 
hint to iterator_facade that the iterator is a constant iterator, and the 
default Reference argument will be correct for all lvalue iterators."

and

"when defining a constant lvalue iterator, the user can pass a const-qualified 
version of the iterator's value_type as iterator_facade's Value parameter and 
omit the Reference parameter which follows."

Am I to understand from this that iterator_facade<Derived,T const,Category> is 
equivalent to iterator_facade<Derived,T,Category,T const&>, and likewise for 
iterator_adaptor?

D.