On Mon, May 27, 2013 at 11:07:38PM +0100, Garth N. Wells wrote: > On 27 May 2013 23:05, Anders Logg <[email protected]> wrote: > > On Mon, May 27, 2013 at 11:00:16PM +0100, Garth N. Wells wrote: > >> On 27 May 2013 22:47, Anders Logg <[email protected]> wrote: > >> > I've just pushed a new typedef 'mesh_index' for unsigned int, similar > >> > to the existing 'la_index'. I suggest we use it in place of unsigned > >> > int wherever we now use unsigned int in place of std::size_t to save > >> > space for local entity indices. > >> > > >> > >> Could you motivate the addition? la_index has a clear motivation - > >> compatibility with linear algebra backends. > > > > So that whenever we use 'unsigned int', it is for a clear purpose - > > either to save space or for compatibility with the index type used by > > the mesh library. It is otherwise likely that it is just using > > unsigned int out of old habit (as I'm prone to). It also has the > > advantage that we can easily change the definition of the type in the > > future if we should need it. > > > > For me a typedef has the opposite effect. It obscures the type. I find > it easy to choose between std::size_t and unsigned int because the > type is obvious. I would prefer to not introduce an unnecessary type.
I find that 'mesh_index' conveys a purpose. Now we use size_t as our default unsigned integer type, except when for some reason we really want something else. There are currently two such examples: for compatibility with the linear algebra backends or for compatibility with the mesh library. It feels natural (to me) to then have la_index and mesh_index. When we then see 'mesh_index' in the code, it signals that whoever wrote that code had a purpose and was not writing unsigned int out of old habit. It's a small change to revert (only introduced so far in the geometry library). I won't insist on it but I'd like to hear some more comments first. -- Anders _______________________________________________ fenics mailing list [email protected] http://fenicsproject.org/mailman/listinfo/fenics
