message: adding std namespace to fabs in qcmx algo to fix mac build error
diff: @@ -173,7 +173,7 @@ double QCMX::measureOperator(const std::shared_ptr<Observable> obs,
  std::complex<double> coeff = f->getCoefficient();
  if (cachedMeasurements.find(f->name()) != cachedMeasurements.end()) {
  total += std::real(coeff * cachedMeasurements[f->name()]);
  - } else if (fabs(coeff) >= threshold) {
  + } else if (std::fabs(coeff) >= threshold) {
  fsToExec.push_back(f);
  coefficients.push_back(coeff);
  }
  