Control on another quantum circuit

[francler1]

I was wondering if it is possible to create a control between one/more qubits and another quantum circuit. I am looking for something like this

qpp:QCircuit qc1(3);
 
// add some gates to qc1 OR even prepare a state for q1

qpp::QCircuit qc2(3);
qc2.compose( qc1 /*target*/, {0,1,2} /* control */ );

I hope this is understandable. In case, the same thing I am looking for can be obtained in Qiskit with:

qreg = QuantumRegister(3)
 
QuantumCircuit qc1(3)

# add some gates or prepare state in qc1

QuantumCircuit qc2(qreg)
qc2.compose(qc1.control(1), qreg[::], inplace=True)

[vsoftco]

@francler1 Thank you for the suggestion. Currently this function is not (yet) implemented. We are working on implementing it, and will close this issue when ready.

[vsoftco]

@francler1 Done in v5.0 d5bfeb2. See qpp::QCircuit::compose_CTRL_circuit().