It is possible to use a single-header library as part of C3 libraries or your project. However, it must be noted that this will inhibit the ability to cross compile, as the compilation of the header is outsourced to the natively installed C compiler.

For that reason it's not an option for the standard library, but can certainly be useful for programs and libraries.

For faults, they are usually defined with `faultdef` which allows you to define one or more faults:

    faultdef SOMETHING_WENT_SIDEWAYS, BIG_OOPS;

Then you use them as if they were constants:

    if (x > 0) return BIG_OOPS?;

If they are defined in another module, say "foo::bar::baz", then:

    if (x > 0) return baz::BIG_OOPS?;

Using path shortening "foo::bar::baz::BIG_OOPS" would also be valid, but is not necessary nor recommended.

  faultdef {
    FOO, // comment
    BAR, // another comment
    BAZ, // yadda
    // Maybe this would work, too (for docgen if available)
    QUX
  }

    faultdef
        FOO, // comment
        BAR, // comment
        QUX; // comment