On Monday, 12 February 2018 at 01:27:19 UTC, Walter Bright wrote:
Know what is a heavyweight problem worth our while? Having dmd
be able to directly read C .h files, so the poor user does not
have to manually translate them.
read directly C++ header files instead of C .h files is what we
should aim for. https://github.com/Syniurge/Calypso/ is actually
already doing just that and already works in many situations (eg
opencv).
Replace the preprocessor in dmc++ with Warp, slice off the back
end, and make it a module that dmd can import.
Wouldn't it be nice to support:
import stdio.h; // Look, Ma! C headers!
There are some intractable issues, and it may be impossible to
get 100% to "it just works", but looking past that it might be
a huge win for us.
llvm+clang is a much better approach, guaranteeing compatibility
with not just C but also and especially C++ (including current
and future C++ standards). Calypso already understands C++
templates, C++ exceptions, can return C++ classes by value (not
just by reference), without the restrictions imposed on
extern(C++) classes/structs.
```
modmap (C++) "opencv2.hpp";
import (C++) cv.Mat;
// can now use C++ templates, functions, macros etc in D code.
```
There are of course a number of issues left to be ironed out, but
it's a much more promising direction than restricting ourselves
to C (as done with `cgo` for go). That's where we should focus
our efforts as far as interop is concerned.
