Function make

src/core/impl/graph/cg_impl.cpp:222–229

    }

    static SymbolVar make(const VarNodeArrayView& inp) {
        mgb_assert(!inp.empty());
        return SymbolVar{inp[0]}
                .node()
                ->owner_graph()
                ->insert_opr(std::make_unique<CallbackCaller>(inp))
                ->output(0);
    }

    void add_callback(const ComputingGraph::Callback& cb, size_t i = 0) {
        mgb_assert(cb && i < m_cb.size());