Fix the compilation and do some cleaning up.

Signed-off-by: Johannes Kalmbach <[email protected]>

benchmark/JoinAlgorithmBenchmark.cpp

@@ -1329,7 +1329,7 @@ class GeneralInterfaceImplementation : public BenchmarkInterface {
   bool addNewRowToBenchmarkTable(
       ResultTable* table,
       const QL_OPT_CONCEPT(
-          (ad_utility::SameAsAny<float, size_t>)) auto changingParameterValue,
+          ad_utility::SameAsAny<float, size_t>) auto changingParameterValue,
       ad_utility::InvocableWithExactReturnType<bool, float, size_t, size_t,
                                                size_t, size_t, float,
                                                float> auto stopFunction,

benchmark/infrastructure/Benchmark.h

@@ -69,7 +69,7 @@ class BenchmarkResults {
   that the new `CopyableUniquePtr` will own.
   */
   template <QL_CONCEPT_OR_TYPENAME(
-      (ad_utility::SameAsAny<ResultTable, ResultEntry, ResultGroup>)) EntryType>
+      ad_utility::SameAsAny<ResultTable, ResultEntry, ResultGroup>) EntryType>
   static EntryType& addEntryToContainerVector(
       PointerVector<EntryType>& targetVector, auto&&... constructorArgs) {
     targetVector.push_back(ad_utility::make_copyable_unique<EntryType>(

src/backports/concepts.h

@@ -13,14 +13,22 @@
 // `QL_OPT_CONCEPT(arg)` which expands to `arg` in C++20 mode, and to nothing in
 // C++17 mode. It can be used to easily opt out of concepts that are only used
 // for documentation and increased safety and not for overload resolution.
-// Example usage:
+// Example usages:
 // `(QL_OPT_CONCEPT(std::view) auto x = someFunction();`
+// `void f(QL_OPT_CONCEPT(std::view) auto x) {...}`
+//
+// `QL_CONCEPT_OR_TYPENAME(arg)` which expands to `arg` in C++20 mode, and to
+// `typename` in C++17 mode. Example: `template
+// <QL_CONCEPT_OR_TYPENAME(ql::same_as<int>) T> void f(){...}`
+//
+// Note: The macros are variadic to allow for commas in the argument (e.g.
+// `QL_OPT_CONCEPT(SameAsAny<int, float>)`.
 #ifdef QLEVER_CPP_17
-#define QL_OPT_CONCEPT(arg)
-#define QL_CONCEPT_OR_TYPENAME(arg) typename
+#define QL_OPT_CONCEPT(...)
+#define QL_CONCEPT_OR_TYPENAME(...) typename
 #else
-#define QL_OPT_CONCEPT(arg) arg
-#define QL_CONCEPT_OR_TYPENAME(arg) arg
+#define QL_OPT_CONCEPT(...) __VA_ARGS__
+#define QL_CONCEPT_OR_TYPENAME(...) __VA_ARGS__
 #endif
 
 // The namespace `ql::concepts` includes concepts that are contained in the

src/util/ConfigManager/ConfigManager.cpp

@@ -255,8 +255,8 @@ requires std::is_object_v<HashMapType> auto ConfigManager::allHashMapEntries(
 }
 
 // ____________________________________________________________________________
-template <QL_CONCEPT_OR_TYPENAME(
-    (SameAsAny<ConfigOption&, const ConfigOption&>)) ReturnReference>
+template <QL_CONCEPT_OR_TYPENAME(SameAsAny<ConfigOption&, const ConfigOption&>)
+              ReturnReference>
 std::vector<std::pair<std::string, ReturnReference>>
 ConfigManager::configurationOptionsImpl(
     SimilarTo<ad_utility::HashMap<std::string, HashMapEntry>> auto&

src/util/ConfigManager/ConfigManager.h

@@ -580,7 +580,8 @@ class ConfigManager {
   @tparam ReturnReference Should be either `ConfigOption&`, or `const
   ConfigOption&`.
   */
-  template <typename ReturnReference>
+  template <QL_CONCEPT_OR_TYPENAME(
+      SameAsAny<ConfigOption&, const ConfigOption&>) ReturnReference>
   static std::vector<std::pair<std::string, ReturnReference>>
   configurationOptionsImpl(
       SimilarTo<ad_utility::HashMap<std::string, HashMapEntry>> auto&

src/util/Iterators.h

@@ -2,13 +2,13 @@
 //  Chair of Algorithms and Data Structures.
 //  Author: Johannes Kalmbach <[email protected]>
 
-#ifndef QLEVER_ITERATORS_H
-#define QLEVER_ITERATORS_H
+#pragma once
 
 #include <cstdint>
 #include <iterator>
 #include <type_traits>
 
+#include "backports/algorithm.h"
 #include "util/Enums.h"
 #include "util/TypeTraits.h"
 
@@ -399,5 +399,3 @@ class InputRangeTypeErased {
   using iterator = typename InputRangeFromGet<ValueType>::Iterator;
 };
 }  // namespace ad_utility
-
-#endif  // QLEVER_ITERATORS_H

src/util/JoinAlgorithms/JoinAlgorithms.h

@@ -9,6 +9,7 @@
 #include <ranges>
 
 #include "backports/algorithm.h"
+#include "backports/concepts.h"
 #include "engine/idTable/IdTable.h"
 #include "global/Id.h"
 #include "util/Generator.h"
@@ -762,13 +763,8 @@ struct BlockZipperJoinImpl {
 #if defined(Side) || defined(Blocks)
 #error Side or Blocks are already defined
 #endif
-#ifdef QLEVER_CPP_17
-#define Side auto
-#define Blocks auto
-#else
-#define Side SameAsAny<LeftSide, RightSide> auto
-#define Blocks SameAsAny<LeftBlocks, RightBlocks> auto
-#endif
+#define Side QL_OPT_CONCEPT(SameAsAny<LeftSide, RightSide>) auto
+#define Blocks QL_OPT_CONCEPT(SameAsAny<LeftBlocks, RightBlocks>) auto
 
   // Type alias for the result of the projection. Elements from the left and
   // right input must be projected to the same type.