Function Rf_lang6 

pub unsafe fn Rf_lang6(
    s: SEXP,
    t: SEXP,
    u: SEXP,
    v: SEXP,
    w: SEXP,
    x: SEXP,
) -> SEXP

Build a language object (call) with function and 5 arguments.

Rust equivalent of R’s inline Rf_lang6(s, t, u, v, w, x). Creates a call like f(arg1, arg2, arg3, arg4, arg5).

Safety

• All SEXPs must be valid
• Must be called from R’s main thread
• Result must be protected from GC