oqgraph-dev team mailing list archive

[Andrew McDonnell <bugs@xxxxxxxxxxxxxxxxxxx>]

Hi Heinz,

is your code up on github or somewhere? These errors can be a bit hard to 
diagnose in isolation.

At a guess though, it looks like there is an equality operator that is a 
member function without a const suffix and its it being used to compare a 
const object.

Although operator== should nearly always be const.

i.e.

class in_edge_iterator /*...*/ {
/*...*/

  bool operator==(const self&) { ... }               <--- wrong

  bool operator==(const self&) const { ... }         <--- correct


HTH,
Andrew



On 18/10/16 05:56, Heinz Wiesinger wrote:
> Hi Andrew,
>
> Thanks for the offer! I'm currently mostly stuck on trying to understand the
> compile error I'm getting (attached). There's simply too much information
> there and I don't know which is the bit I need to focus on.
>
> There is
>
> error: no match for ‘operator==’  (operand types are ‘const
> oqgraph3::in_edge_iterator’ and ‘const oqgraph3::in_edge_iterator’)
> note: candidate: bool oqgraph3::in_edge_iterator::operator==(const self&)
> <near match>
>
> and
>
> error: no match for ‘operator*’ (operand type is ‘const
> oqgraph3::in_edge_iterator’)
> note: candidate: oqgraph3::in_edge_iterator::value_type
> oqgraph3::in_edge_iterator::operator*() <near match>
>
> and
>
> note:   ‘const oqgraph3::in_edge_iterator’ is not derived from ‘const
> boost::iterators::iterator_facade<Derived1, V1, TC1, Reference1, Difference1>’
>
> which look like the most-likely suspects, but there might be something else I
> don't see currently.
>
> If these are indeed the points to tackle, then I'm not really sure what to
> do...
>
> Grs,
> Heinz
>
> On Monday, 17 October 2016 18:08:57 CEST Andrew McDonnell wrote:
> > Hi Heinz
> >
> > Unfortunately I havent looked at any of this for some time.
> >
> > Please do let me know areas you need help, and I can at least try and guide
> > you through, with luck we can muddle through together
> >
> > cheers,
> > Andrew
> >
> > On 08/10/16 19:45, Heinz Wiesinger wrote:
> > > Hello all!
> > >
> > > As part of finishing up the implementation of my "leaves" algorithm I
> > > looked into reverse qraph queries and unfortunately found that none of
> > > them work as expected :(
> > >
> > > Bug filed: https://jira.mariadb.org/browse/MDEV-10980
> > >
> > > I tried looking into the code and saw that a reverse graph is generated
> > >
> > > reverse_graph<Graph> r(share->g);
> > >
> > > but not used. Simply replacing the uses (replace share->g with r) however
> > > results in compiler errors about missing operator overloads in the
> > > iterators. I can try fix this but I would need some pointers, as it is,
> > > it is slightly beyond me :(
> > >
> > > Grs,
> > > Heinz