[boost] N1477 Single Pass Iterators and *r++

From: Beman Dawes (bdawes_at_[hidden])
Date: 2003-07-12 11:59:19

The old input iterator 24.1.1 had a requirement:

   *r++  returned type T, semantics {T tmp= *r; ++r; return tmp; }

The new Single Pass Iterators in N1477 have no such requirement.

That's fine with me - that requirement was a source of bugs in my code and 
violated the rule of least astonishment as far as I was concerned.

But before I remove the test from the filesystem library that verifies the 
old input iterator semantics for directory_iterator, I'd like to verify 
that the omission of *r++ was a design decision rather than an oversight.

The omission of special requirements for *r++ means that Readable and 
Single Pass = Input, as shown in the diagram, is not actually correct, 
unless I'm missing something. Thus perhaps it should be discussed in the 
paper.

--Beman