ImportC and #include files

[jmh530]

On Friday, 28 April 2023 at 14:35:25 UTC, bachmeier wrote:
> [snip]
> Compiling with dmd:
>
> ```
> dmd test.c -P-I../../gsl-2.7.1 -I/usr/include 
> -I/usr/lib/x86_64-linux-gnu/ -L-lgsl -L-lgslcblas -L-lm
> ```

Alright, I built dmd from source on WSL2. I was able to get a 
simple importc program working, but then I got a little stuck 
when I try to make it a little more complicated.

What I want to do is the equivalent of `#include <math.h>` from 
C, but in a D file. I tried using `import math;` with a small 
program that uses it and compiled `dmd file.d -L-lm` but I get a 
message that it can't find the math module.

It seemed to do a bit better when I renamed the file to have a .c 
ending, but then I would have to put the code back in C terms so 
I get errors related to that. When I fix those and replace the 
`import math;` with the include, then it works. But this is just 
compiling the C code with a D compiler. I want to use the C code 
in a D program.