On Sunday, 12 November 2023 at 21:55:31 UTC, Paul Backus wrote:
Personally, my number-one complaint with dmd-as-a-library is
that I am forced to use `extern(C++)` when creating my own
`Visitor` classes.
In [`dmdtags`][1], this requirement has made it necessary for
me to implement my own C++-compatible [`Span`][2] and
[`Appender`][3] types, just to avoid the C++ mangling errors
caused by D's built-in `T[]` slices.
I have no use for overriding AST nodes, but the ability to use
`extern(D)` visitors with dmd-as-a-library would be a welcome
improvement.
The visitor can already be `extern(D)`. Only member functions
overriding those in the base class need to be `extern(C++)`.
Other member functions can then use paratemers, which would be
incompatible with `extern(C++)`.
