On Mon, May 27, 2013 at 11:21:06PM +0100, Garth N. Wells wrote: > On 27 May 2013 23:13, Anders Logg <[email protected]> wrote: > > 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. > > I find the opposite more natural. I would rather see and choose the > type rather than have it obscured by a tyepdef. > > Under what circumstances is the type for mesh_index likely to change?
If we ever get very much larger machines that can handle size_t on each process (or very much smaller so we need short unsigned int). > > 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. > > I don't like either, but la_index is out of necessity. This seems to be a matter of taste. Any more votes in favor of keeping or removing the mesh_index typedef? -- Anders _______________________________________________ fenics mailing list [email protected] http://fenicsproject.org/mailman/listinfo/fenics
