Function wrap_in_quosure 

unsafe fn wrap_in_quosure(new_quosure: SEXP, expr: SEXP, env: SEXP) -> SEXP

new_quosure(quote(<expr>), env), unprotected.

Safety

R’s main thread; new_quosure (from rlang_new_quosure), expr and env rooted, env an environment.