Function erlang_nif_sys::erlang_nif_sys_api::enif_make_map_put

pub unsafe extern "C" fn enif_make_map_put(
    env: *mut ErlNifEnv, 
    map_in: ERL_NIF_TERM, 
    key: ERL_NIF_TERM, 
    value: ERL_NIF_TERM, 
    map_out: *mut ERL_NIF_TERM
) -> c_int

See enif_make_map_put in the Erlang docs.