From fdcf0d649dd3496592d91e6eda1e45b747e31e4e Mon Sep 17 00:00:00 2001
From: Felix Weiglhofer <weiglhofer@fias.uni-frankfurt.de>
Date: Fri, 2 Jun 2023 09:39:14 +0000
Subject: [PATCH] algo: Add support for Enum / String conversion.
---
algo/base/Types.h | 67 +++++++++++++++++++
algo/base/util/SerializableEnum.h | 105 ++++++++++++++++++++++++++++++
2 files changed, 172 insertions(+)
create mode 100644 algo/base/Types.h
create mode 100644 algo/base/util/SerializableEnum.h
diff --git a/algo/base/Types.h b/algo/base/Types.h
new file mode 100644
index 0000000000..6ef3ee98b7
--- /dev/null
+++ b/algo/base/Types.h
@@ -0,0 +1,67 @@
+/* Copyright (C) 2023 FIAS Frankfurt Institute for Advanced Studies, Frankfurt / Main
+ SPDX-License-Identifier: GPL-3.0-only
+ Authors: Felix Weiglhofer [committer] */
+#ifndef CBM_BASE_TYPES_H
+#define CBM_BASE_TYPES_H
+
+#include "util/SerializableEnum.h"
+
+namespace cbm::algo
+{
+
+ enum class Detector
+ {
+ STS,
+ TOF,
+ };
+
+ template<>
+ struct EnumIsSerializable<Detector> : std::true_type {
+ };
+
+ template<>
+ const EnumDict_t<Detector> EnumDict<Detector> = {
+ {"STS", Detector::STS},
+ {"TOF", Detector::TOF},
+ };
+
+ enum class Step
+ {
+ Unpack,
+ DigiTrigger,
+ LocalReco,
+ };
+
+ template<>
+ struct EnumIsSerializable<Step> : std::true_type {
+ };
+
+ template<>
+ const EnumDict_t<Step> EnumDict<Step> = {
+ {"Unpack", Step::Unpack},
+ {"Digitrigger", Step::DigiTrigger},
+ {"Localreco", Step::LocalReco},
+ };
+
+ enum class RecoData
+ {
+ Digi,
+ Cluster,
+ Hit,
+ };
+
+ template<>
+ struct EnumIsSerializable<RecoData> : std::true_type {
+ };
+
+ template<>
+ const EnumDict_t<RecoData> EnumDict<RecoData> = {
+ {"Digi", RecoData::Digi},
+ {"Cluster", RecoData::Cluster},
+ {"Hit", RecoData::Hit},
+ };
+
+} // namespace cbm::algo
+
+
+#endif
diff --git a/algo/base/util/SerializableEnum.h b/algo/base/util/SerializableEnum.h
new file mode 100644
index 0000000000..8921b3ef79
--- /dev/null
+++ b/algo/base/util/SerializableEnum.h
@@ -0,0 +1,105 @@
+/* Copyright (C) 2023 FIAS Frankfurt Institute for Advanced Studies, Frankfurt / Main
+ SPDX-License-Identifier: GPL-3.0-only
+ Authors: Felix Weiglhofer [committer] */
+#ifndef CBM_ALGO_BASE_UTIL_SERIALIZABLEENUM_H
+#define CBM_ALGO_BASE_UTIL_SERIALIZABLEENUM_H
+
+#include <algorithm>
+#include <iostream>
+#include <optional>
+#include <set>
+#include <stdexcept>
+#include <string_view>
+
+#include <fmt/format.h>
+
+namespace cbm::algo
+{
+ /**
+ * @brief Helper class to serialize enums to strings and back.
+ *
+ * @tparam T The enum type.
+ *
+ * To use this class, you need to specialize EnumIsSerializable<T> and EnumStringMap<T>.
+ * Used to indicate that an enum can be converted to / from a string.
+ *
+ * Example:
+ * @code{.cpp}
+ * enum class Detector {
+ * STS,
+ * TOF,
+ * };
+ *
+ * // Set to true to indicate that the enum is serializable.
+ * template<>
+ * struct EnumIsSerializable<Detector> : std::true_type {};
+ *
+ * // Create dictionary to convert enum to string and back.
+ * template<>
+ * const EnumDict_t<Detector> EnumDict<Detector> = {
+ * {"sts", Detector::STS},
+ * {"tof", Detector::TOF},
+ * };
+ *
+ * // Use it like this:
+ * L_(info) << ToString(Detector::STS); // Prints "sts"
+ *
+ * std::optional<Detector> d = FromString<Detector>("tof"); // *d == Detector::TOF
+ * std::optional<Detector> d2 = FromString<Detector>("invalid"); // d2 == std::nullopt
+ * @endcode
+ */
+ template<typename T>
+ struct EnumIsSerializable : std::false_type {
+ };
+
+ template<typename T>
+ using EnumDict_t = std::set<std::pair<std::string_view, T>>;
+
+ template<typename T>
+ inline const EnumDict_t<T> EnumDict;
+
+ template<typename T, typename = std::enable_if_t<EnumIsSerializable<T>::value>>
+ std::optional<T> FromString(std::string_view str)
+ {
+ const auto& set = EnumDict<T>;
+ auto it = std::find_if(set.begin(), set.end(), [str](const auto& pair) { return pair.first == str; });
+ if (it == set.end()) return std::nullopt;
+ return it->second;
+ }
+
+ template<typename T, typename = std::enable_if_t<EnumIsSerializable<T>::value>>
+ std::string_view ToString(T t)
+ {
+ const auto& set = EnumDict<T>;
+ auto it = std::find_if(set.begin(), set.end(), [t](const auto& pair) { return pair.second == t; });
+ if (it == set.end()) throw std::runtime_error(fmt::format("Entry {} for enum missing!", static_cast<int>(t)));
+ return it->first;
+ }
+} // namespace cbm::algo
+
+// Stream operators for enums
+// Placed in global namespace to be found by ADL e.g. for std::ostream_iterator
+namespace std
+{
+ template<typename T, typename = std::enable_if_t<cbm::algo::EnumIsSerializable<T>::value>>
+ std::ostream& operator<<(std::ostream& os, T t)
+ {
+ os << cbm::algo::ToString(t);
+ return os;
+ }
+
+ template<typename T, typename = std::enable_if_t<cbm::algo::EnumIsSerializable<T>::value>>
+ std::istream& operator>>(std::istream& is, T& t)
+ {
+ std::string str;
+ is >> str;
+ auto maybet = cbm::algo::FromString<T>(str);
+
+ if (!maybet) throw std::invalid_argument("Could not parse " + str + " as Enum");
+ t = *maybet;
+
+ return is;
+ }
+} // namespace std
+
+#endif //CBM_ALGO_BASE_UTIL_SERIALIZABLEENUM_H
--
GitLab