Add move semantics to z3::context class

Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>

examples/c++/test_move_context.cpp

@@ -0,0 +1,116 @@
+/*++
+Copyright (c) 2026 Microsoft Corporation
+
+Test file for move semantics of z3::context
+--*/
+
+#include <iostream>
+#include <utility>
+#include <cassert>
+#include "z3++.h"
+
+using namespace z3;
+
+// Test move constructor
+void test_move_constructor() {
+    std::cout << "Testing move constructor...\n";
+    
+    context c1;
+    
+    // Move construct c2 from c1
+    context c2(std::move(c1));
+    
+    // c2 should now own the context, and we can use it
+    expr x = c2.int_const("x");
+    solver s(c2);
+    s.add(x > 0);
+    
+    check_result result = s.check();
+    assert(result == sat);
+    
+    std::cout << "Move constructor test passed!\n";
+}
+
+// Test move assignment operator
+void test_move_assignment() {
+    std::cout << "Testing move assignment operator...\n";
+    
+    context c1;
+    
+    context c2;
+    
+    // Move assign c1 to c2
+    c2 = std::move(c1);
+    
+    // c2 should now own c1's context, and we can use it
+    expr x = c2.int_const("x");
+    solver s(c2);
+    s.add(x > 0);
+    
+    check_result result = s.check();
+    assert(result == sat);
+    
+    std::cout << "Move assignment test passed!\n";
+}
+
+// Test moving context into a function
+context create_context_with_config() {
+    context c;
+    c.set("timeout", 5000);
+    return c; // Will use move constructor
+}
+
+void test_return_by_value() {
+    std::cout << "Testing return by value...\n";
+    
+    context c = create_context_with_config();
+    
+    // Use the returned context
+    expr x = c.int_const("x");
+    solver s(c);
+    s.add(x > 0);
+    
+    check_result result = s.check();
+    assert(result == sat);
+    
+    std::cout << "Return by value test passed!\n";
+}
+
+// Test storing context in a container (e.g., vector)
+void test_vector_storage() {
+    std::cout << "Testing vector storage...\n";
+    
+    std::vector<context> contexts;
+    
+    // Create a context and move it into the vector
+    context c;
+    contexts.push_back(std::move(c));
+    
+    // Use the context from the vector
+    expr x = contexts[0].int_const("x");
+    solver s(contexts[0]);
+    s.add(x > 0);
+    
+    check_result result = s.check();
+    assert(result == sat);
+    
+    std::cout << "Vector storage test passed!\n";
+}
+
+int main() {
+    std::cout << "Running z3::context move semantics tests...\n\n";
+    
+    try {
+        test_move_constructor();
+        test_move_assignment();
+        test_return_by_value();
+        test_vector_storage();
+        
+        std::cout << "\nAll tests passed!\n";
+        return 0;
+    }
+    catch (const exception& e) {
+        std::cerr << "Test failed with exception: " << e << "\n";
+        return 1;
+    }
+}

examples/c++/test_move_simple.cpp

@@ -0,0 +1,45 @@
+/*++
+Copyright (c) 2026 Microsoft Corporation
+
+Simple test file for move semantics of z3::context
+--*/
+
+#include <iostream>
+#include <utility>
+#include "z3++.h"
+
+using namespace z3;
+
+int main() {
+    std::cout << "Test 1: Move constructor\n";
+    {
+        context c1;
+        std::cout << "Created c1\n";
+        
+        context c2(std::move(c1));
+        std::cout << "Moved c1 to c2\n";
+        
+        expr x = c2.int_const("x");
+        std::cout << "Created expression in c2\n";
+    }
+    std::cout << "Test 1 passed!\n\n";
+    
+    std::cout << "Test 2: Move assignment\n";
+    {
+        context c1;
+        std::cout << "Created c1\n";
+        
+        context c2;
+        std::cout << "Created c2\n";
+        
+        c2 = std::move(c1);
+        std::cout << "Move assigned c1 to c2\n";
+        
+        expr x = c2.int_const("x");
+        std::cout << "Created expression in c2\n";
+    }
+    std::cout << "Test 2 passed!\n\n";
+    
+    std::cout << "All tests passed!\n";
+    return 0;
+}