Function ffi_support::call_with_output

pub fn call_with_output<R, F>(
    out_error: &mut ExternError, 
    callback: F
) -> R::Value where
    F: UnwindSafe + FnOnce() -> R,
    R: IntoFfi, 

Call a callback that returns a T while:

• Catching panics, and reporting them to C via [ExternError]
• Converting T to a C-compatible type using [IntoFfi]

Note that you still need to provide an [ExternError] to this function, to report panics.

See [call_with_result] if you'd like to return a Result<T, E> (Note: E must be convertible to [ExternError]).

This (or [call_with_result]) should be in the majority of the FFI functions, see the crate top-level docs for more info.