tl;dr: is it possible to iterate over all classes in a program at
compile time (or possibly all derived classes from a given base
class) to use in a mixin?
Longer version:
Hi! I'm essentially trying to select which class to
instantiate/use as template argument based on a runtime string
(user provided). Something like:
```
string s = args[1];
if (s == "foo") { import foo; return Driver!Foo.run(); }
if (s == "bar") { import bar; return Driver!Bar.run(); }
if (s == "baz") { import baz; return Driver!Baz.run(); }
...
```
Using mixins, I managed to reduce this to:
```
static foreach(name; ["Foo", "Bar", "Baz"])
{
mixin(iq{
if (s == "$(name.toLower)")
{
import $(name.toLower);
return Driver!$(name).run();
}
}.text);
}
```
But it would be even nicer not to have to list the classes by
hand, of course (there might be hundreds eventually).
The closest I got so far is to generate the list of names with a
pre-build command that greps through the sources for relevant
class names, and a file import:
```
const names = import("names.csv").split(",");
```
But that feels like cheating, and it's of course error-prone
since it's text based. Also, if I'm going to run a pre-build
command, I might as well just generate the boilerplate source
code there and just compile the file directly.
Would there a cleaner, D-like way to achieve this? Or a
completely different approach to the problem?
