Function sidecar_require_live 

#[doc(hidden)]
pub fn sidecar_require_live(flag: SEXP) -> bool

Reads the require_live flag the R accessors’ .Call()s pass: TRUE from the $ / [[ / $<- / [[<- field methods, which refuse a restored pointer, FALSE from the standalone accessors, the R6 bindings and the S7 properties, which read a save (#1891). Anything but TRUE reads as false.