Function has_attr_byname 

pub unsafe extern "C" fn has_attr_byname(
    context: *mut c_context,
    value: *const value,
    state: *mut EvalState,
    name: *const c_char,
) -> bool

@brief Check if an attribute name exists on a value @ingroup value_extract @param[out] context Optional, stores error information @param[in] value Nix value to inspect @param[in] state nix evaluator state @param[in] name attribute name @return value, error info via context