include/edm4hep/FeatureFlags.h

0001 /*
0002  * Copyright (c) 2014-2024 Key4hep-Project.
0003  *
0004  * This file is part of Key4hep.
0005  * See https://key4hep.github.io/key4hep-doc/ for further info.
0006  *
0007  * Licensed under the Apache License, Version 2.0 (the "License");
0008  * you may not use this file except in compliance with the License.
0009  * You may obtain a copy of the License at
0010  *
0011  *     http://www.apache.org/licenses/LICENSE-2.0
0012  *
0013  * Unless required by applicable law or agreed to in writing, software
0014  * distributed under the License is distributed on an "AS IS" BASIS,
0015  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
0016  * See the License for the specific language governing permissions and
0017  * limitations under the License.
0018  */
0019 #ifndef EDM4HEP_FEATURE_FLAGS_H
0020 #define EDM4HEP_FEATURE_FLAGS_H
0021
0022 // "Feature flag" to denote an EDM4hep version that already switched the
0023 // MCParticle spin member to helicity. See
0024 // https://github.com/key4hep/EDM4hep/pull/404 for some details on the reasons
0025 // for the switch.
0026 //
0027 // This pre-processor constant was introduced mainly to ease the transition of
0028 // downstream packages between the two versions, as a simple version check was
0029 // not easily possible. The reason being that a "release-like" tag was
0030 // undesirable to avoid advertising perceived stability and any other version
0031 // would have lead to even more comical pre-release tags than v00-99.
0032 //
0033 // Once EDM4hep v01-00 has been released and support for pre-release versions in
0034 // downstream packages has reached a sufficiently low level, it should be
0035 // possible to safely remove this.
0036 #define EDM4HEP_MCPARTICLE_HAS_HELICITY 1
0037
0038 #endif // EDM4HEP_FEATURE_FLAGS_H