Wish: implement %ldccurrentpath% variable for ldc2.conf

[denizzzka]

This would allow to make few standalone standard libraries versions and switch them by selecting desired config file containing compiler options and relative paths to all necessary things

(I can implement this, of course)

[kinke]

With which semantics?

[denizzzka]

Let's say make a d-stdlibs-freertos dir containing library files (in lib/), imports (in import/) and ldc2.conf configuration file in root:

default:
{
    switches = [
        "--mtriple=thumbv7em-unknown-none-eabi",
        "-defaultlib=druntime-ldc,phobos2-ldc"
    ];
    post-switches = [
        "-I%ldccurrentpath%/import/src/",
        "-I%ldccurrentpath%/import/tagged/",
        "-I%ldccurrentpath%/import/phobos/"
    ];
    lib-dirs = [
        "%ldccurrentpath%/lib",
    ];
    rpath = "%ldccurrentpath%/lib";
};

Then, using ldc2 --conf=path/to/d-stdlibs-freertos/ldc2.conf app.d we can compile app.d

[kinke]

So the directory containing the ldc2.conf file. I guess that would be fine, but I'd call it %%ldcconfigpath%% then, analogous to %%ldcbinarypath%%.