Physics/Decay/NoDecay.hpp

0001 // This file is part of the ACTS project.
0002 //
0003 // Copyright (C) 2016 CERN for the benefit of the ACTS project
0004 //
0005 // This Source Code Form is subject to the terms of the Mozilla Public
0006 // License, v. 2.0. If a copy of the MPL was not distributed with this
0007 // file, You can obtain one at https://mozilla.org/MPL/2.0/.
0008
0009 #pragma once
0010
0011 #include "ActsFatras/EventData/Particle.hpp"
0012
0013 #include <array>
0014 #include <limits>
0015
0016 namespace ActsFatras {
0017
0018 /// Decay module that treats all particles as stable.
0019 struct NoDecay {
0020   /// Generate the proper time limit for a particle.
0021   ///
0022   /// @returns Always returns infinity as limit.
0023   template <typename generator_t>
0024   constexpr double generateProperTimeLimit(
0025       generator_t& /* rng */, const Particle& /* particle */) const {
0026     return std::numeric_limits<double>::infinity();
0027   }
0028   /// Decay the particle without generating any descendant particles.
0029   template <typename generator_t>
0030   constexpr std::array<Particle, 0> run(generator_t& /* rng */,
0031                                         const Particle& /* particle */) const {
0032     return {};
0033   }
0034 };
0035
0036 }  // namespace ActsFatras