From ab760b8d93b49693bb6c1d382fdf98cb6ba5a8e7 Mon Sep 17 00:00:00 2001
From: Alan Kerstjens <44154074+AlanKerstjens@users.noreply.github.com>
Date: Sun, 8 May 2022 09:27:58 +0200
Subject: [PATCH] Allow the compiler to generate default ChemicalReaction copy
 assignment operator (#5265)

Co-authored-by: Alan Kerstjens <alan.kerstjens@uantwerpen.be>
---
 Code/GraphMol/ChemReactions/Reaction.h       |  1 -
 Code/GraphMol/ChemReactions/testReaction.cpp | 51 ++++++++++++++++++++
 2 files changed, 51 insertions(+), 1 deletion(-)

diff --git a/Code/GraphMol/ChemReactions/Reaction.h b/Code/GraphMol/ChemReactions/Reaction.h
index 6e90c828ea..ebd230b537 100644
--- a/Code/GraphMol/ChemReactions/Reaction.h
+++ b/Code/GraphMol/ChemReactions/Reaction.h
@@ -357,7 +357,6 @@ class RDKIT_CHEMREACTIONS_EXPORT ChemicalReaction : public RDProps {
   bool df_needsInit{true};
   bool df_implicitProperties{false};
   MOL_SPTR_VECT m_reactantTemplates, m_productTemplates, m_agentTemplates;
-  ChemicalReaction &operator=(const ChemicalReaction &);  // disable assignment
 };
 
 //! tests whether or not the molecule has a substructure match
diff --git a/Code/GraphMol/ChemReactions/testReaction.cpp b/Code/GraphMol/ChemReactions/testReaction.cpp
index 0ee5e45b29..cfb356a20d 100644
--- a/Code/GraphMol/ChemReactions/testReaction.cpp
+++ b/Code/GraphMol/ChemReactions/testReaction.cpp
@@ -7712,6 +7712,56 @@ void testMultiTemplateRxnQueries() {
   delete rxn;
 }
 
+void testChemicalReactionCopyAssignment() {
+  BOOST_LOG(rdInfoLog) << "-------------------------------------" << std::endl;
+  BOOST_LOG(rdInfoLog) << "Testing ChemicalReaction copy assignment operator"
+                       << std::endl;
+
+  std::string rxn_smarts1 =
+    "[C;$(C=O):1][OH1].[N;$(N[#6]);!$(N=*);!$([N-]);!$(N#*);!$([ND3]);!$([ND4]);!$(N[O,N]);!$(N[C,S]=[S,O,N]):2]>>[C:1][N+0:2]";
+  RDKit::ChemicalReaction* rxn1 = RDKit::RxnSmartsToChemicalReaction(rxn_smarts1);
+  rxn1->setImplicitPropertiesFlag(true);
+  rxn1->initReactantMatchers();
+  unsigned int nWarn, nError;
+  TEST_ASSERT(rxn1->validate(nWarn, nError, false));
+  TEST_ASSERT(nWarn == 0 && nError == 0);
+
+  std::string rxn_smarts2 = "[O:1]>>[N:1]";
+  RDKit::ChemicalReaction* rxn2 = RDKit::RxnSmartsToChemicalReaction(rxn_smarts2);
+
+  *rxn2 = *rxn1;
+
+  TEST_ASSERT(rxn2->getImplicitPropertiesFlag());
+  TEST_ASSERT(rxn2->isInitialized());
+
+  RDKit::MOL_SPTR_VECT::const_iterator it1 = rxn1->beginReactantTemplates();
+  RDKit::MOL_SPTR_VECT::const_iterator it2 = rxn2->beginReactantTemplates();
+  RDKit::MOL_SPTR_VECT::const_iterator end_it1 = rxn1->endReactantTemplates();
+  while (it1 != end_it1) {
+    TEST_ASSERT(RDKit::MolToSmiles(**it1) == RDKit::MolToSmiles(**it2));
+    ++it1;
+    ++it2;
+  }
+
+  it1 = rxn1->beginProductTemplates();
+  it2 = rxn2->beginProductTemplates();
+  end_it1 = rxn1->endProductTemplates();
+  while (it1 != end_it1) {
+    TEST_ASSERT(RDKit::MolToSmiles(**it1) == RDKit::MolToSmiles(**it2));
+    ++it1;
+    ++it2;
+  }
+
+  RDKit::MOL_SPTR_VECT reactants;
+  reactants.emplace_back(RDKit::SmilesToMol("CC(=O)O"));
+  reactants.emplace_back(RDKit::SmilesToMol("CCN"));
+  std::vector<RDKit::MOL_SPTR_VECT> products = rxn1->runReactants(reactants);
+  TEST_ASSERT(RDKit::MolToSmiles(*products[0][0]) == "CCNC(C)=O");
+
+  delete rxn1;
+  delete rxn2;
+}
+
 int main() {
   RDLog::InitLogs();
 
@@ -7810,6 +7860,7 @@ int main() {
   testGithub4183();
   testGithub4410();
   testMultiTemplateRxnQueries();
+  testChemicalReactionCopyAssignment();
 
   BOOST_LOG(rdInfoLog)
       << "*******************************************************\n";