# cirq.SupportsDecomposeWithQubits¶

class cirq.SupportsDecomposeWithQubits(*args, **kwargs)[source]

An object that can be decomposed into operations on given qubits.

Returning NotImplemented or None means “not decomposable”. Otherwise an
operation, list of operations, or generally anything meeting the OP_TREE
contract can be returned.
For example, a SWAP gate can be turned into three CNOTs. But in order to
describe those CNOTs one must be able to talk about “the target qubit” and
“the control qubit”. This can only be done once the qubits-to-be-swapped are
known.
The main user of this protocol is GateOperation, which decomposes itself
by delegating to its gate. The qubits argument is needed because gates are
specified independently of target qubits and so must be told the relevant
qubits. A GateOperation implements SupportsDecompose as long as its gate
implements SupportsDecomposeWithQubits.
__init__(*args, **kwargs)