Modernize C++ tests

tests/test_class.cpp

@@ -20,6 +20,7 @@
 #include "local_bindings.h"
 #include "pybind11_tests.h"
 
+#include <memory>
 #include <utility>
 
 PYBIND11_WARNING_DISABLE_MSVC(4324)
@@ -92,8 +93,8 @@ TEST_SUBMODULE(class_, m) {
     // test_inheritance
     class Pet {
     public:
-        Pet(const std::string &name, const std::string &species)
-            : m_name(name), m_species(species) {}
+        Pet(std::string name, std::string species)
+            : m_name(std::move(name)), m_species(std::move(species)) {}
         std::string name() const { return m_name; }
         std::string species() const { return m_species; }
 

tests/test_exceptions.cpp

@@ -90,14 +90,14 @@ class MyException6 : public std::exception {
 };
 
 struct PythonCallInDestructor {
-    explicit PythonCallInDestructor(const py::dict &d) : d(d) {}
+    explicit PythonCallInDestructor(py::dict d) : d(std::move(d)) {}
     ~PythonCallInDestructor() { d["good"] = true; }
 
     py::dict d;
 };
 
 struct PythonAlreadySetInDestructor {
-    explicit PythonAlreadySetInDestructor(const py::str &s) : s(s) {}
+    explicit PythonAlreadySetInDestructor(py::str s) : s(std::move(s)) {}
     ~PythonAlreadySetInDestructor() {
         py::dict foo;
         try {
@@ -112,12 +112,12 @@ struct PythonAlreadySetInDestructor {
 };
 
 struct CustomData {
-    explicit CustomData(const std::string &a) : a(a) {}
+    explicit CustomData(std::string a) : a(std::move(a)) {}
     std::string a;
 };
 
 struct MyException7 {
-    explicit MyException7(const CustomData &message) : message(message) {}
+    explicit MyException7(CustomData message) : message(std::move(message)) {}
     CustomData message;
 };
 

tests/test_kwargs_and_defaults.cpp

@@ -65,7 +65,7 @@ TEST_SUBMODULE(kwargs_and_defaults, m) {
     struct CustomRepr {
         std::string repr_string;
 
-        explicit CustomRepr(const std::string &repr) : repr_string(repr) {}
+        explicit CustomRepr(std::string repr) : repr_string(std::move(repr)) {}
 
         std::string __repr__() const { return repr_string; }
     };

tests/test_pickling.cpp

@@ -66,7 +66,7 @@ TEST_SUBMODULE(pickling, m) {
     // test_roundtrip
     class Pickleable {
     public:
-        explicit Pickleable(const std::string &value) : m_value(value) {}
+        explicit Pickleable(std::string value) : m_value(std::move(value)) {}
         const std::string &value() const { return m_value; }
 
         void setExtra1(int extra1) { m_extra1 = extra1; }
@@ -133,7 +133,7 @@ TEST_SUBMODULE(pickling, m) {
     // test_roundtrip_with_dict
     class PickleableWithDict {
     public:
-        explicit PickleableWithDict(const std::string &value) : value(value) {}
+        explicit PickleableWithDict(std::string value) : value(std::move(value)) {}
 
         std::string value;
         int extra;

tests/test_tagbased_polymorphic.cpp

@@ -11,6 +11,8 @@
 
 #include "pybind11_tests.h"
 
+#include <utility>
+
 struct Animal {
     // Make this type also a "standard" polymorphic type, to confirm that
     // specializing polymorphic_type_hook using enable_if_t still works
@@ -35,7 +37,7 @@ struct Animal {
     const std::string name;
 
 protected:
-    Animal(const std::string &_name, Kind _kind) : kind(_kind), name(_name) {}
+    Animal(std::string _name, Kind _kind) : kind(_kind), name(std::move(_name)) {}
 };
 
 struct Dog : Animal {

tests/test_virtual_functions.cpp

@@ -13,6 +13,7 @@
 #include "pybind11_tests.h"
 
 #include <thread>
+#include <utility>
 
 /* This is an example class that we'll want to be able to extend from Python */
 class ExampleVirt {
@@ -357,7 +358,7 @@ TEST_SUBMODULE(virtual_functions, m) {
         };
         std::string v;
         A a;
-        explicit OverrideTest(const std::string &v) : v{v} {}
+        explicit OverrideTest(std::string v) : v{std::move(v)} {}
         OverrideTest() = default;
         OverrideTest(const OverrideTest &) = delete;
         virtual std::string str_value() { return v; }