d-torrance · Aug 26, 2026 · Aug 26, 2026 · Aug 26, 2026 · Aug 26, 2026 · Aug 26, 2026
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION 3.12)
 
-set(CMAKE_CXX_STANDARD 14)
+set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 project(mathic VERSION 1.4 LANGUAGES CXX)

diff --git a/configure.ac b/configure.ac
@@ -70,6 +70,8 @@ dnl source and binary interface of the library and is not the same as the
 dnl version of the project.
 AC_SUBST([MATHIC_SO_VERSION], [0:4:0])
 
+AX_CXX_COMPILE_STDCXX([17],,[mandatory])
+
 dnl ----- The gtest dependency
 
 AC_ARG_WITH([gtest],
@@ -83,7 +85,6 @@ AC_DEFUN([NO_GTEST_ERROR],
 
 AS_IF([test "x$with_gtest" != "xno"],
      [AC_LANG([C++])
-      AX_CXX_COMPILE_STDCXX([17],,[mandatory])
       AC_CHECK_HEADER([gtest/gtest.h],
          [AC_MSG_CHECKING([for library containing testing::InitGoogleTest])
           SAVELIBS=$LIBS

diff --git a/src/divsim/DivListModel.h b/src/divsim/DivListModel.h
@@ -29,8 +29,8 @@ class DivListModelConfiguration {
   _minRebuild(minRebuild),
   _expQueryCount(0) {}
 
-  static const bool UseLinkedList = ULL;
-  static const bool UseDivMask = UDM;
+  static constexpr bool UseLinkedList = ULL;
+  static constexpr bool UseDivMask = UDM;
 
   bool getDoAutomaticRebuilds() const {return _useAutomaticRebuild;}
   double getRebuildRatio() const {return _rebuildRatio;}

diff --git a/src/divsim/KDTreeModel.h b/src/divsim/KDTreeModel.h
@@ -70,11 +70,11 @@ class KDTreeModelConfiguration {
   double getRebuildRatio() const {return _rebuildRatio;}
   size_t getRebuildMin() const {return _minRebuild;}
 
-  static const bool UseDivMask = UDM;
-  static const bool UseTreeDivMask = UTDM;
-  static const bool PackedTree = PT;
-  static const size_t LeafSize = LS;
-  static const bool AllowRemovals = AR;
+  static constexpr bool UseDivMask = UDM;
+  static constexpr bool UseTreeDivMask = UTDM;
+  static constexpr bool PackedTree = PT;
+  static constexpr size_t LeafSize = LS;
+  static constexpr bool AllowRemovals = AR;
 
   unsigned long long getExpQueryCount() const {return _expQueryCount;}
 

diff --git a/src/mathic/BinaryKDTree.h b/src/mathic/BinaryKDTree.h
@@ -46,7 +46,7 @@ namespace mathic {
     typedef KDTreeInterior Interior;
     typedef KDTreeLeaf Leaf;
     typedef C Configuration;
-    static const bool UseDivMask = C::UseDivMask;
+    static constexpr bool UseDivMask = C::UseDivMask;
 
     class KDTreeNode {
     public:

diff --git a/src/mathic/ComTree.h b/src/mathic/ComTree.h
@@ -88,8 +88,8 @@ namespace mathic {
 
       //private:
       friend class ComTree<Entry, FastIndex>;
-      static const bool fi = FastIndex;
-      static const size_t S = sizeof(Entry);
+      static constexpr bool fi = FastIndex;
+      static constexpr size_t S = sizeof(Entry);
       explicit Node(size_t i): _index(i) {}
       size_t getNormalIndex() const {return fi ? _index / S : _index;}
       size_t _index;

diff --git a/src/mathic/DivFinder.h b/src/mathic/DivFinder.h
@@ -38,9 +38,10 @@
   Returns the number of variables. Variables are indexed from 0 to
   getVarCount() - 1. Must be a positive number.
 
- * static const bool UseDivMask
+ * static constexpr bool UseDivMask
   Set to true to use div masks to speed up queries. This must be a
-  static const data member.
+  compile-time constant data member (static constexpr bool, or static
+  const bool with a constant initializer).
 
  * size_t getUseAutomaticRebuild() const
  * double getRebuildRatio() const

diff --git a/src/mathic/DivList.h b/src/mathic/DivList.h
@@ -53,8 +53,8 @@ namespace mathic {
     typedef typename C::Monomial Monomial;
     typedef typename C::Exponent Exponent;
 
-    static const bool UseLinkedList = C::UseLinkedList;
-    static const bool UseDivMask = C::UseDivMask;
+    static constexpr bool UseLinkedList = C::UseLinkedList;
+    static constexpr bool UseDivMask = C::UseDivMask;
 
   private:
     typedef typename DivMask::Extender<Entry, C::UseDivMask> ExtEntry;

diff --git a/src/mathic/KDTree.h b/src/mathic/KDTree.h
@@ -68,7 +68,7 @@ namespace mathic {
         _divisorCache = 0;
     }
 
-    static const bool UseDivMask = C::UseDivMask;
+    static constexpr bool UseDivMask = C::UseDivMask;
     typedef typename C::Monomial Monomial;
     typedef typename C::Entry Entry;
     typedef typename C::Exponent Exponent;

diff --git a/src/mathic/PackedKDTree.h b/src/mathic/PackedKDTree.h
@@ -30,7 +30,7 @@ namespace mathic {
 
     private:
     typedef C Configuration;
-    static const bool UseDivMask = C::UseDivMask;
+    static constexpr bool UseDivMask = C::UseDivMask;
 
     class Node {
     public:

diff --git a/src/mathic/PairQueue.h b/src/mathic/PairQueue.h
@@ -131,8 +131,7 @@ namespace mathic {
 	// configuration.
 	template<class Configuration>
 	struct SupportRetirement {
-	  // the value field must be static bool const.
-	  static bool const value = true;
+	  static constexpr bool value = true;
 	};
   }
 
@@ -198,7 +197,7 @@ namespace mathic {
 	typedef C Configuration;
 	typedef typename C::PairData PairData;
 	typedef PairQueueNamespace::Index Index;
-	static bool const SupportRetirement =
+	static constexpr bool SupportRetirement =
 	  PairQueueNamespace::SupportRetirement<Configuration>::value;
 
 	// PairQueue stores a copy of the passed in configuration.
@@ -365,7 +364,7 @@ namespace mathic {
 		return mConf.cmpLessThan(cr);
 	  }
 
-      static const bool fastIndex = false;
+      static constexpr bool fastIndex = false;
 
 	private:
 	  Configuration& mConf;

diff --git a/src/mathic/stdinc.h b/src/mathic/stdinc.h
@@ -1,6 +1,10 @@
 #ifndef MATHIC_STDINC_GUARD
 #define MATHIC_STDINC_GUARD
 
+#if __cplusplus < 201703L
+#error "mathic requires C++17 or later"
+#endif
+
 #ifdef _MSC_VER // For Microsoft Compiler in Visual Studio C++.
 // Sometimes you know that a function will be called very rarely so you want to
 // tell the compiler not to inline it even if it could be inlined at only a

diff --git a/src/pqsim/GeobucketModel.h b/src/pqsim/GeobucketModel.h
@@ -18,13 +18,13 @@ class GeobucketModelBase {
   size_t geoBase;
   size_t minBucketSize;
 
-  static const bool trackFront = TrackFront;
-  static const bool minBucketBinarySearch = MinBucketBinarySearch;
-  static const bool premerge = Premerge;
-  static const bool collectMax = CollectMax;
-  static const mathic::GeobucketBucketStorage bucketStorage =
+  static constexpr bool trackFront = TrackFront;
+  static constexpr bool minBucketBinarySearch = MinBucketBinarySearch;
+  static constexpr bool premerge = Premerge;
+  static constexpr bool collectMax = CollectMax;
+  static constexpr mathic::GeobucketBucketStorage bucketStorage =
     (mathic::GeobucketBucketStorage)BucketStorage;
-  static const size_t insertFactor = InsertFactor;
+  static constexpr size_t insertFactor = InsertFactor;
 };
 
 template<

diff --git a/src/pqsim/HeapModel.h b/src/pqsim/HeapModel.h
@@ -6,7 +6,7 @@
 
 template<bool FastIndex>
 struct HeapModelBase {
-  static const bool fastIndex = FastIndex;
+  static constexpr bool fastIndex = FastIndex;
 };
 
 template<bool OnSpans, bool Deduplicate, bool FastIndex>

diff --git a/src/pqsim/Model.h b/src/pqsim/Model.h
@@ -96,7 +96,7 @@ class Model {
     std::vector<Entry>& getPending() {return _pending;}
     size_t getComparisons() const {return _comparisons;}
 
-    static const bool supportDeduplication = Deduplicate;
+    static constexpr bool supportDeduplication = Deduplicate;
 
   private:
     mutable size_t _comparisons;

diff --git a/src/pqsim/TourTreeModel.h b/src/pqsim/TourTreeModel.h
@@ -6,7 +6,7 @@
 
 template<bool FastIndex>
 struct TourTreeModelBase {
-  static const bool fastIndex = FastIndex;
+  static constexpr bool fastIndex = FastIndex;
 };
 
 template<bool OnSpans, bool FastIndex>

diff --git a/src/test/PairQueue.cpp b/src/test/PairQueue.cpp
@@ -40,7 +40,7 @@ namespace mathic {
   namespace PairQueueNamespace {
 	template<>
 	struct SupportRetirement<PQConf> {
-	  static bool const value = false;
+	  static constexpr bool value = false;
 	};
   }
 }
@@ -329,7 +329,7 @@ namespace mathic {
 
 	template<>
 	struct SupportRetirement<PQConDeconCounterConf> {
-	  static bool const value = true;
+	  static constexpr bool value = true;
 	};
   }
 }
@@ -396,8 +396,7 @@ TEST(PairQueue, ConDeconOfPairData) {
 }
 
 TEST(PairQueue, RetirementSetToTrue) {
-  // This test gives an undesigned symbol in the linker now
-  // ASSERT_TRUE(mathic::PairQueue<PQConDeconCounterConf>::SupportRetirement);
+  ASSERT_TRUE(mathic::PairQueue<PQConDeconCounterConf>::SupportRetirement);
   mathic::PairQueue<PQConDeconCounterConf> pq((PQConDeconCounterConf()));
   pq.configuration().owningQueue = &pq;
   mathic::PairQueue<PQConf>::Index* null = 0;