Function clingo_sys::clingo_control_has_const

pub unsafe extern "C" fn clingo_control_has_const(
    control: *const clingo_control_t, 
    name: *const c_char, 
    exists: *mut bool
) -> bool

! Check if there is a constant definition for the given constant. ! ! @param[in] control the target ! @param[in] name the name of the constant ! @param[out] exists whether a matching constant definition exists ! @return whether the call was successful; might set one of the following error codes: ! - ::clingo_error_runtime if constant definition does not exist ! ! @see clingo_control_get_const()