Function ppl_Constraint_System_begin 

pub unsafe extern "C" fn ppl_Constraint_System_begin(
    cs: ppl_const_Constraint_System_t,
    cit: ppl_Constraint_System_const_iterator_t,
) -> c_int

\relates ppl_Constraint_System_tag \brief Assigns to \p cit a const iterator “pointing” to the beginning of the constraint system \p cs.