Function createKrausMap

quest/src/api/channels.cpp:176–200

extern "C" KrausMap createKrausMap(int numQubits, int numOperators) {
    validate_envIsInit(__func__);
    validate_newKrausMapParams(numQubits, numOperators, __func__);

    // validation ensures this never overflows
    qindex numRows = powerOf2(numQubits);

    // attempt to allocate output KrausMap fields (avoiding C++20 designated initialiser)
    KrausMap out;
    out.numQubits = numQubits,
    out.numMatrices = numOperators,
    out.numRows = numRows,
    out.matrices = cpu_allocMatrixList(numRows, numOperators); // is or contains nullptr if failed
    out.superop = allocSuperOp(numQubits); // heap fields are or contain nullptr if failed
    out.isApproxCPTP = util_allocEpsilonSensitiveHeapFlag(); // nullptr if failed

    // free memory before throwing validation error to avoid memory leaks
    freeAllMemoryIfAnyAllocsFailed(out); // sets out.matrices=nullptr if failed
    validate_newKrausMapAllocs(out, __func__);

    // mark CPTP as unknown; it will be lazily evaluated whene a function asserts CPTP-ness
    util_setFlagToUnknown(out.isApproxCPTP);

    return out;
}


extern "C" void destroySuperOp(SuperOp op) {