text: // Copyright 2019-2021 Cambridge Quantum Computing
  //
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  //
  //     http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an "AS IS" BASIS,
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  // See the License for the specific language governing permissions and
  // limitations under the License.
  
  #include "GatePtr.hpp"
  
  #include <memory>
  
  #include "Gate.hpp"
  #include "Ops/OpPtr.hpp"
  #include "Utils/Exceptions.hpp"
  
  namespace tket {
  
  Gate_ptr as_gate_ptr(Op_ptr op) {
    Gate_ptr gp = std::dynamic_pointer_cast<const Gate>(op);
    if (!gp) {
      throw NotValid("Operation is not a gate");
    }
    return gp;
  }
  
  }  // namespace tket
  