Remove awkward operator<< overload, use operator() instead (#2427)

src/solver/expressions/include/antares/solver/expressions/visitors/AstDOTStyleVisitor.h

@@ -107,6 +107,17 @@ class AstDOTStyleVisitor: public NodeVisitor<void, std::ostream&>
      */
     std::string name() const override;
 
+    /**
+     * @brief Outputs the DOT representation of a node to a stream.
+     *
+     * This operator overload facilitates the use of the `AstDOTStyleVisitor` with a node
+     * for direct streaming of the DOT representation.
+     *
+     * @param os The output stream to which the DOT representation is written.
+     * @param root The root of the expression to be output.
+     */
+    void operator()(std::ostream& os, Nodes::Node* root);
+
 private:
     void visit(const Nodes::SumNode* node, std::ostream& os) override;
     void visit(const Nodes::SubtractionNode* node, std::ostream& os) override;
@@ -179,18 +190,4 @@ class AstDOTStyleVisitor: public NodeVisitor<void, std::ostream&>
      */
     unsigned int nodeCount_ = 0;
 };
-
-/**
- * @brief Outputs the DOT representation of a node to a stream.
- *
- * This operator overload facilitates the use of the `AstDOTStyleVisitor` with a node
- * for direct streaming of the DOT representation.
- *
- * @param os The output stream to which the DOT representation is written.
- * @param visitorExpr A pair consisting of the visitor and the node to be output.
- * @return The output stream.
- */
-std::ostream& operator<<(std::ostream& os,
-                         const std::pair<AstDOTStyleVisitor&, Nodes::Node*>& visitorExpr);
-
 } // namespace Antares::Solver::Visitors

src/solver/expressions/visitors/AstDOTStyleVisitor.cpp

@@ -247,13 +247,10 @@ void AstDOTStyleVisitor::EndTreeGraph(std::ostream& os)
     nodeIds_.clear();
 }
 
-std::ostream& operator<<(std::ostream& os,
-                         const std::pair<AstDOTStyleVisitor&, Nodes::Node*>& visitorExpr)
+void AstDOTStyleVisitor::operator()(std::ostream& os, Nodes::Node* root)
 {
-    auto& [visitor, root] = visitorExpr;
-    visitor.NewTreeGraph(os);
-    visitor.dispatch(root, os);
-    visitor.EndTreeGraph(os);
-    return os;
+    NewTreeGraph(os);
+    dispatch(root, os);
+    EndTreeGraph(os);
 }
 } // namespace Antares::Solver::Visitors

src/tests/src/solver/expressions/test_AstDOTStyleVisitor.cpp

@@ -154,9 +154,7 @@ BOOST_FIXTURE_TEST_CASE(tree_with_all_type_node, Fixture)
     std::ostringstream os;
 
     AstDOTStyleVisitor astGraphVisitor;
-
-    std::pair<AstDOTStyleVisitor&, Node*> pair1(astGraphVisitor, makeExpression());
-    os << pair1;
+    astGraphVisitor(os, makeExpression());
 
     // read the content of os
     BOOST_CHECK_EQUAL(expectedDotContent(), os.str());