Phobos in BetterC

[Sebastiaan Koppe]

On Friday, 8 March 2019 at 09:24:25 UTC, Vasyl Teliman wrote:
> Also I would to know what parts of Phobos are available there
> (e.g. std.traits, std.typecons...).

There is no clear rule on which phobos packages work and which 
don't. It all depends on what underlying features the phobos 
package uses. Here is the list of what's not allowed in betterC:

- Garbage Collection
- TypeInfo and ModuleInfo
- Classes
- Built-in threading (e.g. core.thread)
- Dynamic arrays (though slices of static arrays work) and 
associative arrays
- Exceptions
- synchronized and core.sync
- Static module constructors or destructors

Generally anything meta/compile-time works. Packages like 
std.traits / std.meta / std.range / std.algorithm are not an 
issue. You would expect std.typecons.tuple to work as well, but 
it doesn't.

If you are doing ctfe, then you are in for a bummer. Because the 
same restrictions apply there as well. There is supposed to be a 
workaround by including the ctfe file in question via -I on the 
command line, but I could never make it work in dub.

If you encounter something that doesn't work, there are a couple 
of options. Sometimes the function you are trying to use is 
betterC compatible but is inside a package that isn't. Just 
extract it into a separate file. At other times it is because the 
struct has a toString method, or throws an exception. Again, copy 
the relevant part, rip out the toString method and/or replace the 
exception with an assert (of course, after you make sure the 
assert doesn't get triggered). There might also be the option to 
use @nogc exceptions (dip 1008), but I am not sure.

If all that isn't possible, you will have to rewrite the thing in 
question.