Re: [boost] [interprocess] basic_multiallocation_iterator, operator * and -> question

27 Oct 2007


      AMDG

Ion Gaztañaga <igaztanaga <at> gmail.com> writes:
...
You are right. I'm returning the address of a temporary! I think 
conceptually the iterator is wrong. I should return char & for 
operator*() instead of char *. char *should be returned by operator->.
However this makes the code uglier:
multiallocation_iterator it = ...
for(...)
    //placement new
    new(&*it++) T();
instead of
for(...)
    //placement new
    new(*it++) T();
If I want basic_multiallocation_iterator to be a well-formed iterator I 
need to define operator->() so I think I'll need to change the interface 
of this class (I doubt anyone is using it). Give me some time to change 
it and pass the tests again.
It isn't /necessary/.

template<class T, class pointer>
struct arrow_proxy {
    arrow_proxy(const T& t) : impl(t) {}
    pointer operator->() const { return(&impl); }
    T impl;
}

arrow_proxy<value_type, pointer> operator->() {
    return(arrow_proxy<value_type, pointer>(**this));
}

In Christ,
Steven Watanabe