On Friday, 21 March 2014 at 08:05:09 UTC, monarch_dodra wrote:
On Friday, 21 March 2014 at 07:24:43 UTC, Steve Teale wrote:
Can someone tell me where this is written up?
Thanks
Steve
You mean generally, or in phobos?
The rational in phobos is that since it is heavily templated,
it makes sense to pull the imports on a "as needed" basis.
If we placed all the imports needed *anywhere* in the module at
the top, in *all* modules, then importing *anything* in std
would import the world.
for example, something as "dumb" as TypeTuple:
=> need std.typetuple
=> pulls traits
=> pulls typecons and algorithm
=> pulls array, string, uni, ascii, utf, conv
=> pulls everything remaining
The new scheme allows massively reducing these dependencies. At
least, that's the point. cross-module aliasing, and template
constraints tend to make this as smooth as we'd like it.
In end user code, or in non-template code, there is less
rational for doing this. At that point, it only becomes a
style, issue, of whether or not you want to "pollute" your
namespace with imported symbols.
OK, so what happens that's different when I pull in std.typetuple
at the point where I need it? Does that avoid pulling in all the
other stuff?
How does this problem manifest itself - code bloat, or slower
compilations, or what?
Thanks
Steve
