Merge branch 'h2-client' of github.com:drogonframework/drogon into h2-client

Co-authored-by: root <vinicts@protonmail.com>
Co-authored-by: an-tao <antao2002@gmail.com>

drogon_ctl/templates/test_cmake.csp

@@ -6,9 +6,9 @@ add_executable(${PROJECT_NAME} test_main.cc)
 # ##############################################################################
 # If you include the drogon source code locally in your project, use this method
 # to add drogon 
-# target_link_libraries(${PROJECT_NAME}_test PRIVATE drogon)
+# target_link_libraries(${PROJECT_NAME} PRIVATE drogon)
 #
 # and comment out the following lines
 target_link_libraries(${PROJECT_NAME} PRIVATE Drogon::Drogon)
 
-ParseAndAddDrogonTests(${PROJECT_NAME})
+ParseAndAddDrogonTests(${PROJECT_NAME})

lib/inc/drogon/DrObject.h

@@ -57,6 +57,26 @@ class DROGON_EXPORT DrObjectBase
     }
 };
 
+template <typename T>
+struct isAutoCreationClass
+{
+    template <class C>
+    static constexpr auto check(C *)
+        -> std::enable_if_t<std::is_same_v<decltype(C::isAutoCreation), bool>,
+                            bool>
+    {
+        return C::isAutoCreation;
+    }
+
+    template <typename>
+    static constexpr bool check(...)
+    {
+        return false;
+    }
+
+    static constexpr bool value = check<T>(nullptr);
+};
+
 /**
  * a class template to
  * implement the reflection function of creating the class object by class name
@@ -102,23 +122,22 @@ class DrObject : public virtual DrObjectBase
         }
 
         template <typename D>
-        typename std::enable_if<std::is_default_constructible<D>::value,
-                                void>::type
-        registerClass()
-        {
-            DrClassMap::registerClass(
-                className(),
-                []() -> DrObjectBase * { return new T; },
-                []() -> std::shared_ptr<DrObjectBase> {
-                    return std::make_shared<T>();
-                });
-        }
-
-        template <typename D>
-        typename std::enable_if<!std::is_default_constructible<D>::value,
-                                void>::type
-        registerClass()
+        void registerClass()
         {
+            if constexpr (std::is_default_constructible<D>::value)
+            {
+                DrClassMap::registerClass(
+                    className(),
+                    []() -> DrObjectBase * { return new T; },
+                    []() -> std::shared_ptr<DrObjectBase> {
+                        return std::make_shared<T>();
+                    });
+            }
+            else if constexpr (isAutoCreationClass<D>::value)
+            {
+                static_assert(std::is_default_constructible<D>::value,
+                              "Class is not default constructable!");
+            }
         }
     };
 

lib/inc/drogon/HttpBinder.h

@@ -70,6 +70,91 @@ struct BinderArgTypeTraits<const T &>
     static const bool isValid = true;
 };
 
+template <typename T>
+T getHandlerArgumentValue(std::string &&p)
+{
+    if constexpr (internal::CanConstructFromString<T>::value)
+    {
+        return T(std::move(p));
+    }
+    else if constexpr (internal::CanConvertFromStringStream<T>::value)
+    {
+        T value{T()};
+        if (!p.empty())
+        {
+            std::stringstream ss(std::move(p));
+            ss >> value;
+        }
+        return value;
+    }
+    else if constexpr (internal::CanConvertFromString<T>::value)
+    {
+        T value;
+        value = p;
+        return value;
+    }
+    else
+    {
+        LOG_ERROR << "Can't convert string to type " << typeid(T).name();
+        return T();
+    }
+}
+
+template <>
+inline std::string getHandlerArgumentValue<std::string>(std::string &&p)
+{
+    return std::move(p);
+}
+
+template <>
+inline int getHandlerArgumentValue<int>(std::string &&p)
+{
+    return std::stoi(p);
+}
+
+template <>
+inline long getHandlerArgumentValue<long>(std::string &&p)
+{
+    return std::stol(p);
+}
+
+template <>
+inline long long getHandlerArgumentValue<long long>(std::string &&p)
+{
+    return std::stoll(p);
+}
+
+template <>
+inline unsigned long getHandlerArgumentValue<unsigned long>(std::string &&p)
+{
+    return std::stoul(p);
+}
+
+template <>
+inline unsigned long long getHandlerArgumentValue<unsigned long long>(
+    std::string &&p)
+{
+    return std::stoull(p);
+}
+
+template <>
+inline float getHandlerArgumentValue<float>(std::string &&p)
+{
+    return std::stof(p);
+}
+
+template <>
+inline double getHandlerArgumentValue<double>(std::string &&p)
+{
+    return std::stod(p);
+}
+
+template <>
+inline long double getHandlerArgumentValue<long double>(std::string &&p)
+{
+    return std::stold(p);
+}
+
 class HttpBinderBase
 {
   public:
@@ -153,27 +238,22 @@ class HttpBinder : public HttpBinderBase
 
     template <bool isClassFunction = traits::isClassFunction,
               bool isDrObjectClass = traits::isDrObjectClass>
-    typename std::enable_if<isDrObjectClass && isClassFunction, void>::type
-    createHandlerInstance()
-    {
-        auto objPtr =
-            DrClassMap::getSingleInstance<typename traits::class_type>();
-        LOG_TRACE << "create handler class object: " << objPtr.get();
-    }
-
-    template <bool isClassFunction = traits::isClassFunction,
-              bool isDrObjectClass = traits::isDrObjectClass>
-    typename std::enable_if<!isDrObjectClass && isClassFunction, void>::type
-    createHandlerInstance()
-    {
-        auto &obj = getControllerObj<typename traits::class_type>();
-        LOG_TRACE << "create handler class object: " << &obj;
-    }
-
-    template <bool isClassFunction = traits::isClassFunction>
-    typename std::enable_if<!isClassFunction, void>::type
-    createHandlerInstance()
+    void createHandlerInstance()
     {
+        if constexpr (isClassFunction)
+        {
+            if constexpr (isDrObjectClass)
+            {
+                auto objPtr = DrClassMap::getSingleInstance<
+                    typename traits::class_type>();
+                LOG_TRACE << "create handler class object: " << objPtr.get();
+            }
+            else
+            {
+                auto &obj = getControllerObj<typename traits::class_type>();
+                LOG_TRACE << "create handler class object: " << &obj;
+            }
+        }
     }
 
   private:
@@ -184,276 +264,201 @@ class HttpBinder : public HttpBinderBase
     static const size_t argument_count = traits::arity;
     std::string handlerName_;
 
-    template <typename T>
-    typename std::enable_if<internal::CanConvertFromStringStream<T>::value,
-                            void>::type
-    getHandlerArgumentValue(T &value, std::string &&p)
-    {
-        if (!p.empty())
-        {
-            std::stringstream ss(std::move(p));
-            ss >> value;
-        }
-    }
-
-    template <typename T>
-    typename std::enable_if<!(internal::CanConvertFromStringStream<T>::value),
-                            void>::type
-    getHandlerArgumentValue(T &value, std::string &&p)
-    {
-    }
-
-    void getHandlerArgumentValue(std::string &value, std::string &&p)
-    {
-        value = std::move(p);
-    }
-
-    void getHandlerArgumentValue(int &value, std::string &&p)
-    {
-        value = std::stoi(p);
-    }
-
-    void getHandlerArgumentValue(long &value, std::string &&p)
-    {
-        value = std::stol(p);
-    }
-
-    void getHandlerArgumentValue(long long &value, std::string &&p)
-    {
-        value = std::stoll(p);
-    }
-
-    void getHandlerArgumentValue(unsigned long &value, std::string &&p)
-    {
-        value = std::stoul(p);
-    }
-
-    void getHandlerArgumentValue(unsigned long long &value, std::string &&p)
-    {
-        value = std::stoull(p);
-    }
-
-    void getHandlerArgumentValue(float &value, std::string &&p)
-    {
-        value = std::stof(p);
-    }
-
-    void getHandlerArgumentValue(double &value, std::string &&p)
-    {
-        value = std::stod(p);
-    }
-
-    void getHandlerArgumentValue(long double &value, std::string &&p)
-    {
-        value = std::stold(p);
-    }
-
-    template <typename... Values, std::size_t Boundary = argument_count>
-    typename std::enable_if<(sizeof...(Values) < Boundary), void>::type run(
-        std::deque<std::string> &pathArguments,
-        const HttpRequestPtr &req,
-        std::function<void(const HttpResponsePtr &)> &&callback,
-        Values &&...values)
-    {
-        // Call this function recursively until parameter's count equals to the
-        // count of target function parameters
-        static_assert(
-            BinderArgTypeTraits<nth_argument_type<sizeof...(Values)>>::isValid,
-            "your handler argument type must be value type or const left "
-            "reference type or right reference type");
-        using ValueType =
-            typename std::remove_cv<typename std::remove_reference<
-                nth_argument_type<sizeof...(Values)>>::type>::type;
-        ValueType value = ValueType();
-        if (!pathArguments.empty())
-        {
-            std::string v = std::move(pathArguments.front());
-            pathArguments.pop_front();
-            try
-            {
-                if (v.empty() == false)
-                    getHandlerArgumentValue(value, std::move(v));
-            }
-            catch (const std::exception &e)
-            {
-                handleException(e, req, std::move(callback));
-                return;
-            }
-        }
-        else
-        {
-            try
-            {
-                value = req->as<ValueType>();
-            }
-            catch (const std::exception &e)
-            {
-                handleException(e, req, std::move(callback));
-                return;
-            }
-            catch (...)
-            {
-                LOG_ERROR << "Exception not derived from std::exception";
-                return;
-            }
-        }
-
-        run(pathArguments,
-            req,
-            std::move(callback),
-            std::forward<Values>(values)...,
-            std::move(value));
-    }
-
     template <typename... Values,
               std::size_t Boundary = argument_count,
               bool isCoroutine = traits::isCoroutine>
-    typename std::enable_if<(sizeof...(Values) == Boundary) && !isCoroutine,
-                            void>::type
-    run(std::deque<std::string> &,
-        const HttpRequestPtr &req,
-        std::function<void(const HttpResponsePtr &)> &&callback,
-        Values &&...values)
+    void run(std::deque<std::string> &pathArguments,
+             const HttpRequestPtr &req,
+             std::function<void(const HttpResponsePtr &)> &&callback,
+             Values &&...values)
     {
-        try
-        {
-            // Explcit copy because `callFunction` moves it
-            auto cb = callback;
-            callFunction(req, cb, std::move(values)...);
-        }
-        catch (const std::exception &except)
-        {
-            handleException(except, req, std::move(callback));
-        }
-        catch (...)
-        {
-            LOG_ERROR << "Exception not derived from std::exception";
-            return;
-        }
-    }
-#ifdef __cpp_impl_coroutine
-    template <typename... Values,
-              std::size_t Boundary = argument_count,
-              bool isCoroutine = traits::isCoroutine>
-    typename std::enable_if<(sizeof...(Values) == Boundary) && isCoroutine,
-                            void>::type
-    run(std::deque<std::string> &,
-        const HttpRequestPtr &req,
-        std::function<void(const HttpResponsePtr &)> &&callback,
-        Values &&...values)
-    {
-        [this](HttpRequestPtr req,
-               std::function<void(const HttpResponsePtr &)> callback,
-               Values &&...values) -> AsyncTask {
-            try
+        if constexpr (sizeof...(Values) < Boundary)
+        {  // Call this function recursively until parameter's count equals to
+           // the count of target function parameters
+            static_assert(
+                BinderArgTypeTraits<
+                    nth_argument_type<sizeof...(Values)>>::isValid,
+                "your handler argument type must be value type or const left "
+                "reference type or right reference type");
+            using ValueType = std::remove_cv_t<
+                std::remove_reference_t<nth_argument_type<sizeof...(Values)>>>;
+            if (!pathArguments.empty())
             {
-                if constexpr (std::is_same_v<AsyncTask,
-                                             typename traits::return_type>)
+                std::string v{std::move(pathArguments.front())};
+                pathArguments.pop_front();
+                try
+                {
+                    if (!v.empty())
+                    {
+                        auto value =
+                            getHandlerArgumentValue<ValueType>(std::move(v));
+                        run(pathArguments,
+                            req,
+                            std::move(callback),
+                            std::forward<Values>(values)...,
+                            std::move(value));
+                        return;
+                    }
+                }
+                catch (const std::exception &e)
+                {
+                    handleException(e, req, std::move(callback));
+                    return;
+                }
+            }
+            else
+            {
+                try
+                {
+                    auto value = req->as<ValueType>();
+                    run(pathArguments,
+                        req,
+                        std::move(callback),
+                        std::forward<Values>(values)...,
+                        std::move(value));
+                    return;
+                }
+                catch (const std::exception &e)
+                {
+                    handleException(e, req, std::move(callback));
+                    return;
+                }
+                catch (...)
+                {
+                    LOG_ERROR << "Exception not derived from std::exception";
+                    return;
+                }
+            }
+
+            run(pathArguments,
+                req,
+                std::move(callback),
+                std::forward<Values>(values)...,
+                ValueType());
+        }
+        else if constexpr (sizeof...(Values) == Boundary)
+        {
+            if constexpr (!isCoroutine)
+            {
+                try
                 {
                     // Explcit copy because `callFunction` moves it
                     auto cb = callback;
                     callFunction(req, cb, std::move(values)...);
                 }
-                else if constexpr (std::is_same_v<Task<>,
-                                                  typename traits::return_type>)
+                catch (const std::exception &except)
                 {
-                    // Explcit copy because `callFunction` moves it
-                    auto cb = callback;
-                    co_await callFunction(req, cb, std::move(values)...);
+                    handleException(except, req, std::move(callback));
                 }
-                else if constexpr (std::is_same_v<Task<HttpResponsePtr>,
-                                                  typename traits::return_type>)
+                catch (...)
                 {
-                    auto resp =
-                        co_await callFunction(req, std::move(values)...);
-                    callback(std::move(resp));
+                    LOG_ERROR << "Exception not derived from std::exception";
+                    return;
                 }
             }
-            catch (const std::exception &except)
+#ifdef __cpp_impl_coroutine
+            else
             {
-                handleException(except, req, std::move(callback));
+                [this](HttpRequestPtr req,
+                       std::function<void(const HttpResponsePtr &)> callback,
+                       Values &&...values) -> AsyncTask {
+                    try
+                    {
+                        if constexpr (std::is_same_v<
+                                          AsyncTask,
+                                          typename traits::return_type>)
+                        {
+                            // Explcit copy because `callFunction` moves it
+                            auto cb = callback;
+                            callFunction(req, cb, std::move(values)...);
+                        }
+                        else if constexpr (std::is_same_v<
+                                               Task<>,
+                                               typename traits::return_type>)
+                        {
+                            // Explcit copy because `callFunction` moves it
+                            auto cb = callback;
+                            co_await callFunction(req,
+                                                  cb,
+                                                  std::move(values)...);
+                        }
+                        else if constexpr (std::is_same_v<
+                                               Task<HttpResponsePtr>,
+                                               typename traits::return_type>)
+                        {
+                            auto resp =
+                                co_await callFunction(req,
+                                                      std::move(values)...);
+                            callback(std::move(resp));
+                        }
+                    }
+                    catch (const std::exception &except)
+                    {
+                        handleException(except, req, std::move(callback));
+                    }
+                    catch (...)
+                    {
+                        LOG_ERROR
+                            << "Exception not derived from std::exception";
+                    }
+                }(req, std::move(callback), std::move(values)...);
             }
-            catch (...)
-            {
-                LOG_ERROR << "Exception not derived from std::exception";
-            }
-        }(req, std::move(callback), std::move(values)...);
-    }
 #endif
-    template <typename... Values,
-              bool isClassFunction = traits::isClassFunction,
-              bool isDrObjectClass = traits::isDrObjectClass,
-              bool isNormal = std::is_same<typename traits::first_param_type,
-                                           HttpRequestPtr>::value>
-    typename std::enable_if<isClassFunction && !isDrObjectClass && isNormal,
-                            typename traits::return_type>::type
-    callFunction(const HttpRequestPtr &req, Values &&...values)
-    {
-        static auto &obj = getControllerObj<typename traits::class_type>();
-        return (obj.*func_)(req, std::move(values)...);
+        }
     }
 
     template <typename... Values,
               bool isClassFunction = traits::isClassFunction,
               bool isDrObjectClass = traits::isDrObjectClass,
-              bool isNormal = std::is_same<typename traits::first_param_type,
-                                           HttpRequestPtr>::value>
-    typename std::enable_if<isClassFunction && isDrObjectClass && isNormal,
-                            typename traits::return_type>::type
-    callFunction(const HttpRequestPtr &req, Values &&...values)
+              bool isNormal = std::is_same_v<typename traits::first_param_type,
+                                             HttpRequestPtr>>
+    typename traits::return_type callFunction(const HttpRequestPtr &req,
+                                              Values &&...values)
     {
-        static auto objPtr =
-            DrClassMap::getSingleInstance<typename traits::class_type>();
-        return (*objPtr.*func_)(req, std::move(values)...);
-    }
-
-    template <typename... Values,
-              bool isClassFunction = traits::isClassFunction,
-              bool isNormal = std::is_same<typename traits::first_param_type,
-                                           HttpRequestPtr>::value>
-    typename std::enable_if<!isClassFunction && isNormal,
-                            typename traits::return_type>::type
-    callFunction(const HttpRequestPtr &req, Values &&...values)
-    {
-        return func_(req, std::move(values)...);
-    }
-
-    template <typename... Values,
-              bool isClassFunction = traits::isClassFunction,
-              bool isDrObjectClass = traits::isDrObjectClass,
-              bool isNormal = std::is_same<typename traits::first_param_type,
-                                           HttpRequestPtr>::value>
-    typename std::enable_if<isClassFunction && !isDrObjectClass && !isNormal,
-                            typename traits::return_type>::type
-    callFunction(const HttpRequestPtr &req, Values &&...values)
-    {
-        static auto &obj = getControllerObj<typename traits::class_type>();
-        return (obj.*func_)((*req), std::move(values)...);
-    }
-
-    template <typename... Values,
-              bool isClassFunction = traits::isClassFunction,
-              bool isDrObjectClass = traits::isDrObjectClass,
-              bool isNormal = std::is_same<typename traits::first_param_type,
-                                           HttpRequestPtr>::value>
-    typename std::enable_if<isClassFunction && isDrObjectClass && !isNormal,
-                            typename traits::return_type>::type
-    callFunction(const HttpRequestPtr &req, Values &&...values)
-    {
-        static auto objPtr =
-            DrClassMap::getSingleInstance<typename traits::class_type>();
-        return (*objPtr.*func_)((*req), std::move(values)...);
-    }
-
-    template <typename... Values,
-              bool isClassFunction = traits::isClassFunction,
-              bool isNormal = std::is_same<typename traits::first_param_type,
-                                           HttpRequestPtr>::value>
-    typename std::enable_if<!isClassFunction && !isNormal,
-                            typename traits::return_type>::type
-    callFunction(const HttpRequestPtr &req, Values &&...values)
-    {
-        return func_((*req), std::move(values)...);
+        if constexpr (isNormal)
+        {
+            if constexpr (isClassFunction)
+            {
+                if constexpr (!isDrObjectClass)
+                {
+                    static auto &obj =
+                        getControllerObj<typename traits::class_type>();
+                    return (obj.*func_)(req, std::move(values)...);
+                }
+                else
+                {
+                    static auto objPtr = DrClassMap::getSingleInstance<
+                        typename traits::class_type>();
+                    return (*objPtr.*func_)(req, std::move(values)...);
+                }
+            }
+            else
+            {
+                return func_(req, std::move(values)...);
+            }
+        }
+        else
+        {
+            if constexpr (isClassFunction)
+            {
+                if constexpr (!isDrObjectClass)
+                {
+                    static auto &obj =
+                        getControllerObj<typename traits::class_type>();
+                    return (obj.*func_)((*req), std::move(values)...);
+                }
+                else
+                {
+                    static auto objPtr = DrClassMap::getSingleInstance<
+                        typename traits::class_type>();
+                    return (*objPtr.*func_)((*req), std::move(values)...);
+                }
+            }
+            else
+            {
+                return func_((*req), std::move(values)...);
+            }
+        }
     }
 };
 

lib/inc/drogon/HttpController.h

@@ -59,7 +59,7 @@ template <typename T, bool AutoCreation = true>
 class HttpController : public DrObject<T>, public HttpControllerBase
 {
   public:
-    static const bool isAutoCreation = AutoCreation;
+    static constexpr bool isAutoCreation = AutoCreation;
 
   protected:
     template <typename FUNCTION>

lib/inc/drogon/drogon_test.h

@@ -69,11 +69,10 @@ struct is_printable : std::false_type
 };
 
 template <typename _Tp>
-struct is_printable<_Tp,
-                    typename std::enable_if<
-                        std::is_same<decltype(std::cout << std::declval<_Tp>()),
-                                     std::ostream &>::value>::type>
-    : std::true_type
+struct is_printable<
+    _Tp,
+    std::enable_if_t<std::is_same_v<decltype(std::cout << std::declval<_Tp>()),
+                                    std::ostream &>>> : std::true_type
 {
 };
 
@@ -167,10 +166,10 @@ inline std::string attemptPrint(T &&v)
 
     // Poor man's if constexpr because SFINAE don't disambiguate between
     // possible resolutions
-    return typename std::conditional<
-        std::is_convertible<T, std::string_view>::value,
-        internal::StringPrinter,
-        DefaultPrinter>::type()(v);
+    return
+        typename std::conditional_t<std::is_convertible_v<T, std::string_view>,
+                                    internal::StringPrinter,
+                                    DefaultPrinter>()(v);
 }
 
 // Specializations to reduce template construction
@@ -281,7 +280,7 @@ struct Lhs
     template <typename RhsType>
     ComparsionResult operator&&(const RhsType &rhs)
     {
-        static_assert(!std::is_same<RhsType, void>::value,
+        static_assert(!std::is_same_v<RhsType, void>,
                       " && is not supported in expression decomposition");
         return {};
     }
@@ -289,7 +288,7 @@ struct Lhs
     template <typename RhsType>
     ComparsionResult operator||(const RhsType &rhs)
     {
-        static_assert(!std::is_same<RhsType, void>::value,
+        static_assert(!std::is_same_v<RhsType, void>,
                       " || is not supported in expression decomposition");
         return {};
     }
@@ -297,7 +296,7 @@ struct Lhs
     template <typename RhsType>
     ComparsionResult operator|(const RhsType &rhs)
     {
-        static_assert(!std::is_same<RhsType, void>::value,
+        static_assert(!std::is_same_v<RhsType, void>,
                       " | is not supported in expression decomposition");
         return {};
     }
@@ -305,7 +304,7 @@ struct Lhs
     template <typename RhsType>
     ComparsionResult operator&(const RhsType &rhs)
     {
-        static_assert(!std::is_same<RhsType, void>::value,
+        static_assert(!std::is_same_v<RhsType, void>,
                       " & is not supported in expression decomposition");
         return {};
     }

lib/inc/drogon/plugins/Plugin.h

@@ -106,8 +106,7 @@ class DROGON_EXPORT PluginBase : public virtual DrObjectBase,
 template <typename T>
 struct IsPlugin
 {
-    using TYPE =
-        typename std::remove_cv<typename std::remove_reference<T>::type>::type;
+    using TYPE = std::remove_cv_t<typename std::remove_reference_t<T>>;
 
     static int test(void *)
     {

lib/inc/drogon/utils/FunctionTraits.h

@@ -50,7 +50,7 @@ struct FunctionTraits;
 template <typename Function>
 struct FunctionTraits
     : public FunctionTraits<
-          decltype(&std::remove_reference<Function>::type::operator())>
+          decltype(&std::remove_reference_t<Function>::operator())>
 {
     static const bool isClassFunction = false;
     static const bool isDrObjectClass = false;
@@ -190,7 +190,7 @@ struct FunctionTraits<ReturnType (*)(Arguments...)>
 
     template <std::size_t Index>
     using argument =
-        typename std::tuple_element<Index, std::tuple<Arguments...>>::type;
+        typename std::tuple_element_t<Index, std::tuple<Arguments...>>;
 
     static const std::size_t arity = sizeof...(Arguments);
     using class_type = void;

lib/inc/drogon/utils/OStringStream.h

@@ -37,8 +37,7 @@ struct CanConvertToString
     static no test(...);
 
   public:
-    static constexpr bool value =
-        std::is_same<decltype(test<Type>(0)), yes>::value;
+    static constexpr bool value = std::is_same_v<decltype(test<Type>(0)), yes>;
 };
 }  // namespace internal
 
@@ -53,21 +52,20 @@ class OStringStream
     }
 
     template <typename T>
-    std::enable_if_t<!internal::CanConvertToString<T>::value, OStringStream &>
-    operator<<(T &&value)
+    OStringStream &operator<<(T &&value)
     {
-        std::stringstream ss;
-        ss << std::forward<T>(value);
-        buffer_.append(ss.str());
-        return *this;
-    }
-
-    template <typename T>
-    std::enable_if_t<internal::CanConvertToString<T>::value, OStringStream &>
-    operator<<(T &&value)
-    {
-        buffer_.append(std::to_string(std::forward<T>(value)));
-        return *this;
+        if constexpr (internal::CanConvertToString<T>::value)
+        {
+            buffer_.append(std::to_string(std::forward<T>(value)));
+            return *this;
+        }
+        else
+        {
+            std::stringstream ss;
+            ss << std::forward<T>(value);
+            buffer_.append(ss.str());
+            return *this;
+        }
     }
 
     template <int N>

lib/inc/drogon/utils/Utilities.h

@@ -53,9 +53,43 @@ struct CanConvertFromStringStream
 
   public:
     static constexpr bool value =
-        std::is_same<decltype(test<T>(nullptr, std::stringstream())),
-                     yes>::value;
+        std::is_same_v<decltype(test<T>(nullptr, std::stringstream())), yes>;
 };
+
+template <typename T>
+struct CanConstructFromString
+{
+  private:
+    using yes = std::true_type;
+    using no = std::false_type;
+
+    template <typename U>
+    static auto test(U *p) -> decltype(U(std::string{}), yes());
+
+    template <typename>
+    static no test(...);
+
+  public:
+    static constexpr bool value =
+        std::is_same_v<decltype(test<T>(nullptr)), yes>;
+};
+
+template <typename T>
+struct CanConvertFromString
+{
+  private:
+    using yes = std::true_type;
+    using no = std::false_type;
+    template <class U>
+    static auto test(U *p) -> decltype(*p = std::string(), yes());
+    template <class>
+    static no test(...);
+
+  public:
+    static constexpr bool value =
+        std::is_same_v<decltype(test<T>(nullptr)), yes>;
+};
+
 }  // namespace internal
 
 namespace utils
@@ -79,7 +113,8 @@ DROGON_EXPORT std::string genRandomString(int length);
 
 /// Convert a binary string to hex format
 DROGON_EXPORT std::string binaryStringToHex(const unsigned char *ptr,
-                                            size_t length);
+                                            size_t length,
+                                            bool lowerCase = false);
 
 /// Get a binary string from hexadecimal format
 DROGON_EXPORT std::string hexToBinaryString(const char *ptr, size_t length);
@@ -88,6 +123,11 @@ DROGON_EXPORT std::string hexToBinaryString(const char *ptr, size_t length);
 DROGON_EXPORT std::vector<char> hexToBinaryVector(const char *ptr,
                                                   size_t length);
 
+DROGON_EXPORT void binaryStringToHex(const char *ptr,
+                                     size_t length,
+                                     char *out,
+                                     bool lowerCase = false);
+
 /// Split the string into multiple separated strings.
 /**
  * @param acceptEmptyString if true, empty strings are accepted in the
@@ -106,7 +146,7 @@ DROGON_EXPORT std::set<std::string> splitStringToSet(
     const std::string &separator);
 
 /// Get UUID string.
-DROGON_EXPORT std::string getUuid();
+DROGON_EXPORT std::string getUuid(bool lowercase = true);
 
 /// Get the encoded length of base64.
 constexpr size_t base64EncodedLength(size_t in_len, bool padded = true)
@@ -396,24 +436,22 @@ DROGON_EXPORT bool secureRandomBytes(void *ptr, size_t size);
 DROGON_EXPORT std::string secureRandomString(size_t size);
 
 template <typename T>
-typename std::enable_if<internal::CanConvertFromStringStream<T>::value, T>::type
-fromString(const std::string &p) noexcept(false)
+T fromString(const std::string &p) noexcept(false)
 {
-    T value{};
-    if (!p.empty())
+    if constexpr (internal::CanConvertFromStringStream<T>::value)
     {
-        std::stringstream ss(p);
-        ss >> value;
+        T value{};
+        if (!p.empty())
+        {
+            std::stringstream ss(p);
+            ss >> value;
+        }
+        return value;
+    }
+    else
+    {
+        throw std::runtime_error("Bad type conversion");
     }
-    return value;
-}
-
-template <typename T>
-typename std::enable_if<!(internal::CanConvertFromStringStream<T>::value),
-                        T>::type
-fromString(const std::string &) noexcept(false)
-{
-    throw std::runtime_error("Bad type conversion");
 }
 
 template <>

lib/src/Http2Transport.cc

@@ -1375,7 +1375,6 @@ void Http2Transport::sendFrame(const internal::H2Frame &frame, int32_t streamId)
 
 void Http2Transport::sendBufferedData()
 {
-    LOG_WARN << "Sending buffered data. Size: " << batchedSendBuffer.size();
     if (batchedSendBuffer.size() == 0)
         return;
     OByteStream buffer;

lib/src/HttpAppFrameworkImpl.cc

@@ -777,14 +777,14 @@ void HttpAppFrameworkImpl::findSessionForRequest(const HttpRequestImplPtr &req)
     if (useSession_)
     {
         std::string sessionId = req->getCookie(sessionCookieKey_);
-        bool needSetJsessionid = false;
+        bool needSetSessionid = false;
         if (sessionId.empty())
         {
-            sessionId = utils::getUuid();
-            needSetJsessionid = true;
+            sessionId = sessionIdGeneratorCallback_();
+            needSetSessionid = true;
         }
         req->setSession(
-            sessionManagerPtr_->getSession(sessionId, needSetJsessionid));
+            sessionManagerPtr_->getSession(sessionId, needSetSessionid));
     }
 }
 

lib/src/HttpAppFrameworkImpl.h

@@ -25,6 +25,7 @@
 #include <string>
 #include <vector>
 #include "SessionManager.h"
+#include "drogon/utils/Utilities.h"
 #include "impl_forwards.h"
 
 namespace trantor
@@ -250,7 +251,9 @@ class HttpAppFrameworkImpl final : public HttpAppFramework
     HttpAppFramework &setSessionIdGenerator(
         SessionManager::IdGeneratorCallback idGeneratorCallback = nullptr)
     {
-        sessionIdGeneratorCallback_ = idGeneratorCallback;
+        sessionIdGeneratorCallback_ =
+            idGeneratorCallback ? idGeneratorCallback
+                                : []() { return utils::getUuid(true); };
         return *this;
     }
 

lib/src/HttpRequestImpl.cc

@@ -760,7 +760,7 @@ void HttpRequestImpl::appendToBody(const char *data, size_t length)
 void HttpRequestImpl::createTmpFile()
 {
     auto tmpfile = HttpAppFrameworkImpl::instance().getUploadPath();
-    auto fileName = utils::getUuid();
+    auto fileName = utils::getUuid(false);
     tmpfile.append("/tmp/")
         .append(1, fileName[0])
         .append(1, fileName[1])

lib/src/SessionManager.cc

@@ -13,7 +13,6 @@
  */
 
 #include "SessionManager.h"
-#include <drogon/utils/Utilities.h>
 
 using namespace drogon;
 
@@ -27,8 +26,7 @@ SessionManager::SessionManager(
       timeout_(timeout),
       sessionStartAdvices_(startAdvices),
       sessionDestroyAdvices_(destroyAdvices),
-      idGeneratorCallback_(idGeneratorCallback ? idGeneratorCallback
-                                               : utils::getUuid)
+      idGeneratorCallback_(idGeneratorCallback)
 {
     if (timeout_ > 0)
     {

lib/src/SessionManager.h

@@ -37,7 +37,7 @@ class SessionManager : public trantor::NonCopyable
         size_t timeout,
         const std::vector<AdviceStartSessionCallback> &startAdvices,
         const std::vector<AdviceDestroySessionCallback> &destroyAdvices,
-        IdGeneratorCallback idGeneratorCallback = nullptr);
+        IdGeneratorCallback idGeneratorCallback);
 
     ~SessionManager()
     {

lib/src/Utilities.cc

@@ -289,31 +289,55 @@ std::string hexToBinaryString(const char *ptr, size_t length)
     return ret;
 }
 
-std::string binaryStringToHex(const unsigned char *ptr, size_t length)
+DROGON_EXPORT void binaryStringToHex(const char *ptr,
+                                     size_t length,
+                                     char *out,
+                                     bool lowerCase)
 {
-    std::string idString;
     for (size_t i = 0; i < length; ++i)
     {
         int value = (ptr[i] & 0xf0) >> 4;
         if (value < 10)
         {
-            idString.append(1, char(value + 48));
+            out[i * 2] = char(value + 48);
         }
         else
         {
-            idString.append(1, char(value + 55));
+            if (!lowerCase)
+            {
+                out[i * 2] = char(value + 55);
+            }
+            else
+            {
+                out[i * 2] = char(value + 87);
+            }
         }
 
         value = (ptr[i] & 0x0f);
         if (value < 10)
         {
-            idString.append(1, char(value + 48));
+            out[i * 2 + 1] = char(value + 48);
         }
         else
         {
-            idString.append(1, char(value + 55));
+            if (!lowerCase)
+            {
+                out[i * 2 + 1] = char(value + 55);
+            }
+            else
+            {
+                out[i * 2 + 1] = char(value + 87);
+            }
         }
     }
+}
+
+std::string binaryStringToHex(const unsigned char *ptr,
+                              size_t length,
+                              bool lowercase)
+{
+    std::string idString(length * 2, '\0');
+    binaryStringToHex((const char *)ptr, length, &idString[0], lowercase);
     return idString;
 }
 
@@ -342,7 +366,23 @@ std::set<std::string> splitStringToSet(const std::string &str,
     return ret;
 }
 
-std::string getUuid()
+inline std::string createUuidString(const char *str, size_t len, bool lowercase)
+{
+    assert(len == 16);
+    std::string uuid(36, '\0');
+    binaryStringToHex(str, 4, &uuid[0], lowercase);
+    uuid[8] = '-';
+    binaryStringToHex(str + 4, 2, &uuid[9], lowercase);
+    uuid[13] = '-';
+    binaryStringToHex(str + 6, 2, &uuid[14], lowercase);
+    uuid[18] = '-';
+    binaryStringToHex(str + 8, 2, &uuid[19], lowercase);
+    uuid[23] = '-';
+    binaryStringToHex(str + 10, 6, &uuid[24], lowercase);
+    return uuid;
+}
+
+std::string getUuid(bool lowercase)
 {
 #if USE_OSSP_UUID
     uuid_t *uuid;
@@ -352,7 +392,7 @@ std::string getUuid()
     size_t len{0};
     uuid_export(uuid, UUID_FMT_BIN, &str, &len);
     uuid_destroy(uuid);
-    std::string ret{binaryStringToHex((const unsigned char *)str, len)};
+    auto ret = createUuidString(str, len, lowercase);
     free(str);
     return ret;
 #elif defined __FreeBSD__ || defined __OpenBSD__
@@ -370,7 +410,7 @@ std::string getUuid()
     uuid_enc_be(binstr, uuid);
 #endif /* _BYTE_ORDER == _LITTLE_ENDIAN */
     delete uuid;
-    std::string ret{binaryStringToHex((const unsigned char *)binstr, 16)};
+    auto ret = createUuidString(binstr, 16, lowercase);
     free(binstr);
     return ret;
 #elif defined _WIN32
@@ -379,7 +419,7 @@ std::string getUuid()
     char tempStr[100];
     auto len = snprintf(tempStr,
                         sizeof(tempStr),
-                        "%08X-%04X-%04X-%02X%02X-%02X%02X%02X%02X%02X%02X",
+                        "%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x",
                         uu.Data1,
                         uu.Data2,
                         uu.Data3,
@@ -395,7 +435,8 @@ std::string getUuid()
 #else
     uuid_t uu;
     uuid_generate(uu);
-    return binaryStringToHex(uu, 16);
+    auto uuid = createUuidString((const char *)uu, 16, lowercase);
+    return uuid;
 #endif
 }
 

lib/tests/CMakeLists.txt

@@ -25,7 +25,9 @@ set(UNITTEST_SOURCES
     unittests/StringOpsTest.cc
     unittests/ControllerCreationTest.cc
     unittests/MultiPartParserTest.cc
-    unittests/SlashRemoverTest.cc)
+    unittests/SlashRemoverTest.cc
+    unittests/UuidUnittest.cc
+)
 
 if(DROGON_CXX_STANDARD GREATER_EQUAL 20 AND HAS_COROUTINE)
   set(UNITTEST_SOURCES ${UNITTEST_SOURCES} unittests/CoroutineTest.cc)

lib/tests/unittests/UuidUnittest.cc

@@ -0,0 +1,17 @@
+#include <string_view>
+#include <drogon/utils/Utilities.h>
+#include <iostream>
+#include <drogon/drogon_test.h>
+
+DROGON_TEST(UuidTest)
+{
+    auto uuid = drogon::utils::getUuid();
+
+    std::cout << "uuid: " << uuid << std::endl;
+
+    CHECK(uuid[8] == '-');
+    CHECK(uuid[13] == '-');
+    CHECK(uuid[18] == '-');
+    CHECK(uuid[23] == '-');
+    CHECK(uuid.size() == 36);
+}

orm_lib/inc/drogon/orm/BaseBuilder.h

@@ -167,7 +167,6 @@ class BaseBuilder
     }
 
   public:
-#ifdef __cpp_if_constexpr
     static ResultType convert_result(const Result &r)
     {
         if constexpr (SelectAll)
@@ -198,48 +197,6 @@ class BaseBuilder
             }
         }
     }
-#else
-    template <bool SA = SelectAll,
-              bool SI = Single,
-              std::enable_if_t<SA, std::nullptr_t> = nullptr,
-              std::enable_if_t<SI, std::nullptr_t> = nullptr>
-    static inline T convert_result(const Result &r)
-    {
-        return T(r[0]);
-    }
-
-    template <bool SA = SelectAll,
-              bool SI = Single,
-              std::enable_if_t<SA, std::nullptr_t> = nullptr,
-              std::enable_if_t<!SI, std::nullptr_t> = nullptr>
-    static inline std::vector<T> convert_result(const Result &r)
-    {
-        std::vector<T> ret;
-        for (const Row &row : r)
-        {
-            ret.template emplace_back(T(row));
-        }
-        return ret;
-    }
-
-    template <bool SA = SelectAll,
-              bool SI = Single,
-              std::enable_if_t<!SA, std::nullptr_t> = nullptr,
-              std::enable_if_t<SI, std::nullptr_t> = nullptr>
-    static inline Row convert_result(const Result &r)
-    {
-        return r[0];
-    }
-
-    template <bool SA = SelectAll,
-              bool SI = Single,
-              std::enable_if_t<!SA, std::nullptr_t> = nullptr,
-              std::enable_if_t<!SI, std::nullptr_t> = nullptr>
-    static inline Result convert_result(const Result &r)
-    {
-        return r;
-    }
-#endif
 
     inline ResultType execSync(const DbClientPtr &client)
     {

orm_lib/inc/drogon/orm/CoroMapper.h

@@ -80,13 +80,12 @@ class CoroMapper : public Mapper<T>
 
     inline internal::MapperAwaiter<T> findByPrimaryKey(const TraitsPKType &key)
     {
-        if constexpr (!std::is_same<typename T::PrimaryKeyType, void>::value)
+        if constexpr (!std::is_same_v<typename T::PrimaryKeyType, void>)
         {
             auto lb = [this, key](SingleRowCallback &&callback,
                                   ExceptPtrCallback &&errCallback) mutable {
-                static_assert(
-                    !std::is_same<typename T::PrimaryKeyType, void>::value,
-                    "No primary key in the table!");
+                static_assert(!std::is_same_v<typename T::PrimaryKeyType, void>,
+                              "No primary key in the table!");
                 static_assert(
                     internal::has_sqlForFindingByPrimaryKey<T>::value,
                     "No function member named sqlForFindingByPrimaryKey, "
@@ -417,9 +416,8 @@ class CoroMapper : public Mapper<T>
         auto lb = [this, obj](CountCallback &&callback,
                               ExceptPtrCallback &&errCallback) {
             this->clear();
-            static_assert(
-                !std::is_same<typename T::PrimaryKeyType, void>::value,
-                "No primary key in the table!");
+            static_assert(!std::is_same_v<typename T::PrimaryKeyType, void>,
+                          "No primary key in the table!");
             std::string sql = "update ";
             sql += T::tableName;
             sql += " set ";
@@ -530,9 +528,8 @@ class CoroMapper : public Mapper<T>
         auto lb = [this, obj](CountCallback &&callback,
                               ExceptPtrCallback &&errCallback) {
             this->clear();
-            static_assert(
-                !std::is_same<typename T::PrimaryKeyType, void>::value,
-                "No primary key in the table!");
+            static_assert(!std::is_same_v<typename T::PrimaryKeyType, void>,
+                          "No primary key in the table!");
             std::string sql = "delete from ";
             sql += T::tableName;
             sql += " ";
@@ -555,9 +552,8 @@ class CoroMapper : public Mapper<T>
         auto lb = [this, criteria](CountCallback &&callback,
                                    ExceptPtrCallback &&errCallback) {
             this->clear();
-            static_assert(
-                !std::is_same<typename T::PrimaryKeyType, void>::value,
-                "No primary key in the table!");
+            static_assert(!std::is_same_v<typename T::PrimaryKeyType, void>,
+                          "No primary key in the table!");
             std::string sql = "delete from ";
             sql += T::tableName;
 
@@ -584,7 +580,7 @@ class CoroMapper : public Mapper<T>
     inline internal::MapperAwaiter<size_t> deleteByPrimaryKey(
         const TraitsPKType &key)
     {
-        static_assert(!std::is_same<typename T::PrimaryKeyType, void>::value,
+        static_assert(!std::is_same_v<typename T::PrimaryKeyType, void>,
                       "No primary key in the table!");
         static_assert(
             internal::has_sqlForDeletingByPrimaryKey<T>::value,

orm_lib/inc/drogon/orm/FunctionTraits.h

@@ -110,9 +110,10 @@ struct FunctionTraits<ReturnType (*)(Arguments...)>
 
     static const std::size_t arity = sizeof...(Arguments);
 
-    // static const bool isSqlCallback = false;
     static const bool isSqlCallback = true;
     static const bool isStepResultCallback = true;
+    static const bool isExceptCallback = false;
+    static const bool isPtr = false;
 };
 }  // namespace internal
 }  // namespace orm

orm_lib/inc/drogon/orm/Mapper.h

@@ -62,8 +62,7 @@ struct has_sqlForFindingByPrimaryKey
     static no test(...);
 
   public:
-    static constexpr bool value =
-        std::is_same<decltype(test<T>(0)), yes>::value;
+    static constexpr bool value = std::is_same_v<decltype(test<T>(0)), yes>;
 };
 
 template <typename T>
@@ -81,8 +80,7 @@ struct has_sqlForDeletingByPrimaryKey
     static no test(...);
 
   public:
-    static constexpr bool value =
-        std::is_same<decltype(test<T>(0)), yes>::value;
+    static constexpr bool value = std::is_same_v<decltype(test<T>(0)), yes>;
 };
 }  // namespace internal
 
@@ -185,7 +183,7 @@ class Mapper
     using CountCallback = std::function<void(const size_t)>;
 
     using TraitsPKType = typename internal::
-        Traits<T, !std::is_same<typename T::PrimaryKeyType, void>::value>::type;
+        Traits<T, !std::is_same_v<typename T::PrimaryKeyType, void>>::type;
 
     /**
      * @brief Find a record by the primary key.
@@ -196,53 +194,48 @@ class Mapper
      */
 
     template <typename U = T>
-    inline typename std::enable_if<
-        !std::is_same<typename U::PrimaryKeyType, void>::value,
-        T>::type
-    findByPrimaryKey(const TraitsPKType &key) noexcept(false)
+    inline T findByPrimaryKey(const TraitsPKType &key) noexcept(false)
     {
-        static_assert(!std::is_same<typename T::PrimaryKeyType, void>::value,
-                      "No primary key in the table!");
-        static_assert(
-            internal::has_sqlForFindingByPrimaryKey<T>::value,
-            "No function member named sqlForFindingByPrimaryKey, please "
-            "make sure that the model class is generated by the latest "
-            "version of drogon_ctl");
-        // return findOne(Criteria(T::primaryKeyName, key));
-        std::string sql = T::sqlForFindingByPrimaryKey();
-        if (forUpdate_)
+        if constexpr (!std::is_same_v<typename U::PrimaryKeyType, void>)
         {
-            sql += " for update";
+            static_assert(!std::is_same_v<typename T::PrimaryKeyType, void>,
+                          "No primary key in the table!");
+            static_assert(
+                internal::has_sqlForFindingByPrimaryKey<T>::value,
+                "No function member named sqlForFindingByPrimaryKey, please "
+                "make sure that the model class is generated by the latest "
+                "version of drogon_ctl");
+            // return findOne(Criteria(T::primaryKeyName, key));
+            std::string sql = T::sqlForFindingByPrimaryKey();
+            if (forUpdate_)
+            {
+                sql += " for update";
+            }
+            clear();
+            Result r(nullptr);
+            {
+                auto binder = *client_ << std::move(sql);
+                outputPrimeryKeyToBinder(key, binder);
+                binder << Mode::Blocking;
+                binder >> [&r](const Result &result) { r = result; };
+                binder.exec();  // exec may be throw exception;
+            }
+            if (r.size() == 0)
+            {
+                throw UnexpectedRows("0 rows found");
+            }
+            else if (r.size() > 1)
+            {
+                throw UnexpectedRows("Found more than one row");
+            }
+            auto row = r[0];
+            return T(row);
         }
-        clear();
-        Result r(nullptr);
+        else
         {
-            auto binder = *client_ << std::move(sql);
-            outputPrimeryKeyToBinder(key, binder);
-            binder << Mode::Blocking;
-            binder >> [&r](const Result &result) { r = result; };
-            binder.exec();  // exec may be throw exception;
+            LOG_FATAL << "The table must have a primary key";
+            abort();
         }
-        if (r.size() == 0)
-        {
-            throw UnexpectedRows("0 rows found");
-        }
-        else if (r.size() > 1)
-        {
-            throw UnexpectedRows("Found more than one row");
-        }
-        auto row = r[0];
-        return T(row);
-    }
-
-    template <typename U = T>
-    inline typename std::enable_if<
-        std::is_same<typename U::PrimaryKeyType, void>::value,
-        T>::type
-    findByPrimaryKey(const TraitsPKType &key) noexcept(false)
-    {
-        LOG_FATAL << "The table must have a primary key";
-        abort();
     }
 
     /**
@@ -253,56 +246,49 @@ class Mapper
      * @param ecb Is called when an error occurs or a record cannot be found.
      */
     template <typename U = T>
-    inline typename std::enable_if<
-        !std::is_same<typename U::PrimaryKeyType, void>::value,
-        void>::type
-    findByPrimaryKey(const TraitsPKType &key,
-                     const SingleRowCallback &rcb,
-                     const ExceptionCallback &ecb) noexcept
+    inline void findByPrimaryKey(const TraitsPKType &key,
+                                 const SingleRowCallback &rcb,
+                                 const ExceptionCallback &ecb) noexcept
     {
-        static_assert(!std::is_same<typename T::PrimaryKeyType, void>::value,
-                      "No primary key in the table!");
-        static_assert(
-            internal::has_sqlForFindingByPrimaryKey<T>::value,
-            "No function member named sqlForFindingByPrimaryKey, please "
-            "make sure that the model class is generated by the latest "
-            "version of drogon_ctl");
-        // findOne(Criteria(T::primaryKeyName, key), rcb, ecb);
-        std::string sql = T::sqlForFindingByPrimaryKey();
-        if (forUpdate_)
+        if constexpr (!std::is_same_v<typename U::PrimaryKeyType, void>)
         {
-            sql += " for update";
+            static_assert(!std::is_same_v<typename T::PrimaryKeyType, void>,
+                          "No primary key in the table!");
+            static_assert(
+                internal::has_sqlForFindingByPrimaryKey<T>::value,
+                "No function member named sqlForFindingByPrimaryKey, please "
+                "make sure that the model class is generated by the latest "
+                "version of drogon_ctl");
+            // findOne(Criteria(T::primaryKeyName, key), rcb, ecb);
+            std::string sql = T::sqlForFindingByPrimaryKey();
+            if (forUpdate_)
+            {
+                sql += " for update";
+            }
+            clear();
+            auto binder = *client_ << std::move(sql);
+            outputPrimeryKeyToBinder(key, binder);
+            binder >> [ecb, rcb](const Result &r) {
+                if (r.size() == 0)
+                {
+                    ecb(UnexpectedRows("0 rows found"));
+                }
+                else if (r.size() > 1)
+                {
+                    ecb(UnexpectedRows("Found more than one row"));
+                }
+                else
+                {
+                    rcb(T(r[0]));
+                }
+            };
+            binder >> ecb;
+        }
+        else
+        {
+            LOG_FATAL << "The table must have a primary key";
+            abort();
         }
-        clear();
-        auto binder = *client_ << std::move(sql);
-        outputPrimeryKeyToBinder(key, binder);
-        binder >> [ecb, rcb](const Result &r) {
-            if (r.size() == 0)
-            {
-                ecb(UnexpectedRows("0 rows found"));
-            }
-            else if (r.size() > 1)
-            {
-                ecb(UnexpectedRows("Found more than one row"));
-            }
-            else
-            {
-                rcb(T(r[0]));
-            }
-        };
-        binder >> ecb;
-    }
-
-    template <typename U = T>
-    inline typename std::enable_if<
-        std::is_same<typename U::PrimaryKeyType, void>::value,
-        void>::type
-    findByPrimaryKey(const TraitsPKType &key,
-                     const SingleRowCallback &rcb,
-                     const ExceptionCallback &ecb) noexcept
-    {
-        LOG_FATAL << "The table must have a primary key";
-        abort();
     }
 
     /**
@@ -315,60 +301,56 @@ class Mapper
      * user calls the get() method of the future object.
      */
     template <typename U = T>
-    inline typename std::enable_if<
-        !std::is_same<typename U::PrimaryKeyType, void>::value,
-        std::future<T>>::type
-    findFutureByPrimaryKey(const TraitsPKType &key) noexcept
+    inline std::future<T> findFutureByPrimaryKey(
+        const TraitsPKType &key) noexcept
     {
-        static_assert(!std::is_same<typename T::PrimaryKeyType, void>::value,
-                      "No primary key in the table!");
-        static_assert(
-            internal::has_sqlForFindingByPrimaryKey<T>::value,
-            "No function member named sqlForFindingByPrimaryKey, please "
-            "make sure that the model class is generated by the latest "
-            "version of drogon_ctl");
-        // return findFutureOne(Criteria(T::primaryKeyName, key));
-        std::string sql = T::sqlForFindingByPrimaryKey();
-        if (forUpdate_)
+        if constexpr (!std::is_same_v<typename U::PrimaryKeyType, void>)
         {
-            sql += " for update";
+            static_assert(!std::is_same_v<typename T::PrimaryKeyType, void>,
+                          "No primary key in the table!");
+            static_assert(
+                internal::has_sqlForFindingByPrimaryKey<T>::value,
+                "No function member named sqlForFindingByPrimaryKey, please "
+                "make sure that the model class is generated by the latest "
+                "version of drogon_ctl");
+            // return findFutureOne(Criteria(T::primaryKeyName, key));
+            std::string sql = T::sqlForFindingByPrimaryKey();
+            if (forUpdate_)
+            {
+                sql += " for update";
+            }
+            clear();
+            auto binder = *client_ << std::move(sql);
+            outputPrimeryKeyToBinder(key, binder);
+
+            std::shared_ptr<std::promise<T>> prom =
+                std::make_shared<std::promise<T>>();
+            binder >> [prom](const Result &r) {
+                if (r.size() == 0)
+                {
+                    prom->set_exception(std::make_exception_ptr(
+                        UnexpectedRows("0 rows found")));
+                }
+                else if (r.size() > 1)
+                {
+                    prom->set_exception(std::make_exception_ptr(
+                        UnexpectedRows("Found more than one row")));
+                }
+                else
+                {
+                    prom->set_value(T(r[0]));
+                }
+            };
+            binder >>
+                [prom](const std::exception_ptr &e) { prom->set_exception(e); };
+            binder.exec();
+            return prom->get_future();
+        }
+        else
+        {
+            LOG_FATAL << "The table must have a primary key";
+            abort();
         }
-        clear();
-        auto binder = *client_ << std::move(sql);
-        outputPrimeryKeyToBinder(key, binder);
-
-        std::shared_ptr<std::promise<T>> prom =
-            std::make_shared<std::promise<T>>();
-        binder >> [prom](const Result &r) {
-            if (r.size() == 0)
-            {
-                prom->set_exception(
-                    std::make_exception_ptr(UnexpectedRows("0 rows found")));
-            }
-            else if (r.size() > 1)
-            {
-                prom->set_exception(std::make_exception_ptr(
-                    UnexpectedRows("Found more than one row")));
-            }
-            else
-            {
-                prom->set_value(T(r[0]));
-            }
-        };
-        binder >>
-            [prom](const std::exception_ptr &e) { prom->set_exception(e); };
-        binder.exec();
-        return prom->get_future();
-    }
-
-    template <typename U = T>
-    inline typename std::enable_if<
-        std::is_same<typename U::PrimaryKeyType, void>::value,
-        std::future<U>>::type
-    findFutureByPrimaryKey(const TraitsPKType &key) noexcept
-    {
-        LOG_FATAL << "The table must have a primary key";
-        abort();
     }
 
     /**
@@ -701,67 +683,57 @@ class Mapper
     }
 
     template <typename PKType = decltype(T::primaryKeyName)>
-    typename std::enable_if<std::is_same<const std::string, PKType>::value,
-                            void>::type
-    makePrimaryKeyCriteria(std::string &sql)
+    void makePrimaryKeyCriteria(std::string &sql)
     {
-        sql += " where ";
-        sql += T::primaryKeyName;
-        sql += " = $?";
-    }
-
-    template <typename PKType = decltype(T::primaryKeyName)>
-    typename std::enable_if<
-        std::is_same<const std::vector<std::string>, PKType>::value,
-        void>::type
-    makePrimaryKeyCriteria(std::string &sql)
-    {
-        sql += " where ";
-        for (size_t i = 0; i < T::primaryKeyName.size(); ++i)
+        if constexpr (std::is_same_v<const std::string, PKType>)
         {
-            sql += T::primaryKeyName[i];
+            sql += " where ";
+            sql += T::primaryKeyName;
             sql += " = $?";
-            if (i < (T::primaryKeyName.size() - 1))
+        }
+        else if constexpr (std::is_same_v<const std::vector<std::string>,
+                                          PKType>)
+        {
+            sql += " where ";
+            for (size_t i = 0; i < T::primaryKeyName.size(); ++i)
             {
-                sql += " and ";
+                sql += T::primaryKeyName[i];
+                sql += " = $?";
+                if (i < (T::primaryKeyName.size() - 1))
+                {
+                    sql += " and ";
+                }
             }
         }
     }
 
     template <typename PKType = decltype(T::primaryKeyName)>
-    typename std::enable_if<std::is_same<const std::string, PKType>::value,
-                            void>::type
-    outputPrimeryKeyToBinder(const TraitsPKType &pk,
-                             internal::SqlBinder &binder)
+    void outputPrimeryKeyToBinder(const TraitsPKType &pk,
+                                  internal::SqlBinder &binder)
     {
-        binder << pk;
-    }
-
-    template <typename PKType = decltype(T::primaryKeyName)>
-    typename std::enable_if<
-        std::is_same<const std::vector<std::string>, PKType>::value,
-        void>::type
-    outputPrimeryKeyToBinder(const TraitsPKType &pk,
-                             internal::SqlBinder &binder)
-    {
-        tupleToBinder<typename T::PrimaryKeyType>(pk, binder);
+        if constexpr (std::is_same_v<const std::string, PKType>)
+        {
+            binder << pk;
+        }
+        else if constexpr (std::is_same_v<const std::vector<std::string>,
+                                          PKType>)
+        {
+            tupleToBinder<typename T::PrimaryKeyType>(pk, binder);
+        }
     }
 
     template <typename TP, ssize_t N = std::tuple_size<TP>::value>
-    typename std::enable_if<(N > 1), void>::type tupleToBinder(
-        const TP &t,
-        internal::SqlBinder &binder)
+    void tupleToBinder(const TP &t, internal::SqlBinder &binder)
     {
-        tupleToBinder<TP, N - 1>(t, binder);
-        binder << std::get<N - 1>(t);
-    }
-
-    template <typename TP, ssize_t N = std::tuple_size<TP>::value>
-    typename std::enable_if<(N == 1), void>::type tupleToBinder(
-        const TP &t,
-        internal::SqlBinder &binder)
-    {
-        binder << std::get<0>(t);
+        if constexpr (N > 1)
+        {
+            tupleToBinder<TP, N - 1>(t, binder);
+            binder << std::get<N - 1>(t);
+        }
+        else if constexpr (N == 1)
+        {
+            binder << std::get<0>(t);
+        }
     }
 
     std::string replaceSqlPlaceHolder(const std::string &sqlStr,
@@ -1321,7 +1293,7 @@ template <typename T>
 inline size_t Mapper<T>::update(const T &obj) noexcept(false)
 {
     clear();
-    static_assert(!std::is_same<typename T::PrimaryKeyType, void>::value,
+    static_assert(!std::is_same_v<typename T::PrimaryKeyType, void>,
                   "No primary key in the table!");
     std::string sql = "update ";
     sql += T::tableName;
@@ -1394,7 +1366,7 @@ inline void Mapper<T>::update(const T &obj,
                               const ExceptionCallback &ecb) noexcept
 {
     clear();
-    static_assert(!std::is_same<typename T::PrimaryKeyType, void>::value,
+    static_assert(!std::is_same_v<typename T::PrimaryKeyType, void>,
                   "No primary key in the table!");
     std::string sql = "update ";
     sql += T::tableName;
@@ -1457,7 +1429,7 @@ template <typename T>
 inline std::future<size_t> Mapper<T>::updateFuture(const T &obj) noexcept
 {
     clear();
-    static_assert(!std::is_same<typename T::PrimaryKeyType, void>::value,
+    static_assert(!std::is_same_v<typename T::PrimaryKeyType, void>,
                   "No primary key in the table!");
     std::string sql = "update ";
     sql += T::tableName;
@@ -1529,7 +1501,7 @@ template <typename T>
 inline size_t Mapper<T>::deleteOne(const T &obj) noexcept(false)
 {
     clear();
-    static_assert(!std::is_same<typename T::PrimaryKeyType, void>::value,
+    static_assert(!std::is_same_v<typename T::PrimaryKeyType, void>,
                   "No primary key in the table!");
     std::string sql = "delete from ";
     sql += T::tableName;
@@ -1556,7 +1528,7 @@ inline void Mapper<T>::deleteOne(const T &obj,
                                  const ExceptionCallback &ecb) noexcept
 {
     clear();
-    static_assert(!std::is_same<typename T::PrimaryKeyType, void>::value,
+    static_assert(!std::is_same_v<typename T::PrimaryKeyType, void>,
                   "No primary key in the table!");
     std::string sql = "delete from ";
     sql += T::tableName;
@@ -1575,7 +1547,7 @@ template <typename T>
 inline std::future<size_t> Mapper<T>::deleteFutureOne(const T &obj) noexcept
 {
     clear();
-    static_assert(!std::is_same<typename T::PrimaryKeyType, void>::value,
+    static_assert(!std::is_same_v<typename T::PrimaryKeyType, void>,
                   "No primary key in the table!");
     std::string sql = "delete from ";
     sql += T::tableName;
@@ -1599,7 +1571,7 @@ template <typename T>
 inline size_t Mapper<T>::deleteBy(const Criteria &criteria) noexcept(false)
 {
     clear();
-    static_assert(!std::is_same<typename T::PrimaryKeyType, void>::value,
+    static_assert(!std::is_same_v<typename T::PrimaryKeyType, void>,
                   "No primary key in the table!");
     std::string sql = "delete from ";
     sql += T::tableName;
@@ -1631,7 +1603,7 @@ inline void Mapper<T>::deleteBy(const Criteria &criteria,
                                 const ExceptionCallback &ecb) noexcept
 {
     clear();
-    static_assert(!std::is_same<typename T::PrimaryKeyType, void>::value,
+    static_assert(!std::is_same_v<typename T::PrimaryKeyType, void>,
                   "No primary key in the table!");
     std::string sql = "delete from ";
     sql += T::tableName;
@@ -1657,7 +1629,7 @@ inline std::future<size_t> Mapper<T>::deleteFutureBy(
     const Criteria &criteria) noexcept
 {
     clear();
-    static_assert(!std::is_same<typename T::PrimaryKeyType, void>::value,
+    static_assert(!std::is_same_v<typename T::PrimaryKeyType, void>,
                   "No primary key in the table!");
     std::string sql = "delete from ";
     sql += T::tableName;
@@ -1797,7 +1769,7 @@ template <typename T>
 inline size_t Mapper<T>::deleteByPrimaryKey(
     const typename Mapper<T>::TraitsPKType &key) noexcept(false)
 {
-    static_assert(!std::is_same<typename T::PrimaryKeyType, void>::value,
+    static_assert(!std::is_same_v<typename T::PrimaryKeyType, void>,
                   "No primary key in the table!");
     static_assert(internal::has_sqlForDeletingByPrimaryKey<T>::value,
                   "No function member named sqlForDeletingByPrimaryKey, please "
@@ -1821,7 +1793,7 @@ inline void Mapper<T>::deleteByPrimaryKey(
     const CountCallback &rcb,
     const ExceptionCallback &ecb) noexcept
 {
-    static_assert(!std::is_same<typename T::PrimaryKeyType, void>::value,
+    static_assert(!std::is_same_v<typename T::PrimaryKeyType, void>,
                   "No primary key in the table!");
     static_assert(internal::has_sqlForDeletingByPrimaryKey<T>::value,
                   "No function member named sqlForDeletingByPrimaryKey, please "
@@ -1839,7 +1811,7 @@ template <typename T>
 inline std::future<size_t> Mapper<T>::deleteFutureByPrimaryKey(
     const typename Mapper<T>::TraitsPKType &key) noexcept
 {
-    static_assert(!std::is_same<typename T::PrimaryKeyType, void>::value,
+    static_assert(!std::is_same_v<typename T::PrimaryKeyType, void>,
                   "No primary key in the table!");
     static_assert(internal::has_sqlForDeletingByPrimaryKey<T>::value,
                   "No function member named sqlForDeletingByPrimaryKey, please "

orm_lib/inc/drogon/orm/SqlBinder.h

@@ -203,83 +203,78 @@ class CallbackHolder : public CallbackHolderBase
     static const size_t argumentCount = traits::arity;
 
     template <bool isStep = traits::isStepResultCallback>
-    typename std::enable_if<isStep, void>::type run(const Result &result)
+    void run(const Result &result)
     {
-        if (result.empty())
+        if constexpr (isStep)
         {
+            if (result.empty())
+            {
+                run(nullptr, true);
+                return;
+            }
+            for (auto const &row : result)
+            {
+                run(&row, false);
+            }
             run(nullptr, true);
-            return;
         }
-        for (auto const &row : result)
+        else
         {
-            run(&row, false);
+            static_assert(argumentCount == 0,
+                          "Your sql callback function type is wrong!");
+            function_(result);
         }
-        run(nullptr, true);
-    }
-
-    template <bool isStep = traits::isStepResultCallback>
-    typename std::enable_if<!isStep, void>::type run(const Result &result)
-    {
-        static_assert(argumentCount == 0,
-                      "Your sql callback function type is wrong!");
-        function_(result);
     }
 
     template <typename... Values, std::size_t Boundary = argumentCount>
-    typename std::enable_if<(sizeof...(Values) < Boundary), void>::type run(
-        const Row *const row,
-        bool isNull,
-        Values &&...values)
+    void run(const Row *const row, bool isNull, Values &&...values)
     {
-        // call this function recursively until parameter's count equals to the
-        // count of target function parameters
-        static_assert(
-            CallbackArgTypeTraits<NthArgumentType<sizeof...(Values)>>::isValid,
-            "your sql callback function argument type must be value "
-            "type or "
-            "const "
-            "left-reference type");
-        using ValueType =
-            typename std::remove_cv<typename std::remove_reference<
-                NthArgumentType<sizeof...(Values)>>::type>::type;
-        ValueType value = ValueType();
-        if (row && row->size() > sizeof...(Values))
+        if constexpr (sizeof...(Values) < Boundary)
         {
-            // if(!VectorTypeTraits<ValueType>::isVector)
-            //     value = (*row)[sizeof...(Values)].as<ValueType>();
-            // else
-            //     ; // value =
-            //     (*row)[sizeof...(Values)].asArray<VectorTypeTraits<ValueType>::ItemsType>();
-            value =
-                makeValue<ValueType>((*row)[(Row::SizeType)sizeof...(Values)]);
+            // call this function recursively until parameter's count equals to
+            // the count of target function parameters
+            static_assert(
+                CallbackArgTypeTraits<
+                    NthArgumentType<sizeof...(Values)>>::isValid,
+                "your sql callback function argument type must be value "
+                "type or "
+                "const "
+                "left-reference type");
+            using ValueType =
+                typename std::remove_cv<typename std::remove_reference<
+                    NthArgumentType<sizeof...(Values)>>::type>::type;
+            ValueType value = ValueType();
+            if (row && row->size() > sizeof...(Values))
+            {
+                // if(!VectorTypeTraits<ValueType>::isVector)
+                //     value = (*row)[sizeof...(Values)].as<ValueType>();
+                // else
+                //     ; // value =
+                //     (*row)[sizeof...(Values)].asArray<VectorTypeTraits<ValueType>::ItemsType>();
+                value = makeValue<ValueType>(
+                    (*row)[(Row::SizeType)sizeof...(Values)]);
+            }
+
+            run(row, isNull, std::forward<Values>(values)..., std::move(value));
+        }
+        else if constexpr (sizeof...(Values) == Boundary)
+        {
+            function_(isNull, std::move(values)...);
         }
-
-        run(row, isNull, std::forward<Values>(values)..., std::move(value));
-    }
-
-    template <typename... Values, std::size_t Boundary = argumentCount>
-    typename std::enable_if<(sizeof...(Values) == Boundary), void>::type run(
-        const Row *const,
-        bool isNull,
-        Values &&...values)
-    {
-        function_(isNull, std::move(values)...);
     }
 
     template <typename ValueType>
-    typename std::enable_if<VectorTypeTraits<ValueType>::isVector,
-                            ValueType>::type
-    makeValue(const Field &field)
+    ValueType makeValue(const Field &field)
     {
-        return field.asArray<typename VectorTypeTraits<ValueType>::ItemsType>();
-    }
-
-    template <typename ValueType>
-    typename std::enable_if<!VectorTypeTraits<ValueType>::isVector,
-                            ValueType>::type
-    makeValue(const Field &field)
-    {
-        return field.as<ValueType>();
+        if constexpr (VectorTypeTraits<ValueType>::isVector)
+        {
+            return field
+                .asArray<typename VectorTypeTraits<ValueType>::ItemsType>();
+        }
+        else
+        {
+            return field.as<ValueType>();
+        }
     }
 };
 
@@ -346,51 +341,38 @@ class DROGON_EXPORT SqlBinder : public trantor::NonCopyable
     template <typename CallbackType,
               typename traits =
                   FunctionTraits<typename std::decay<CallbackType>::type>>
-    typename std::enable_if<traits::isExceptCallback && traits::isPtr,
-                            self>::type &
-    operator>>(CallbackType &&callback)
+    self &operator>>(CallbackType &&callback)
     {
-        // LOG_DEBUG << "ptr callback";
-        isExceptionPtr_ = true;
-        exceptionPtrCallback_ = std::forward<CallbackType>(callback);
-        return *this;
-    }
-
-    template <typename CallbackType,
-              typename traits =
-                  FunctionTraits<typename std::decay<CallbackType>::type>>
-    typename std::enable_if<traits::isExceptCallback && !traits::isPtr,
-                            self>::type &
-    operator>>(CallbackType &&callback)
-    {
-        isExceptionPtr_ = false;
-        exceptionCallback_ = std::forward<CallbackType>(callback);
-        return *this;
-    }
-
-    template <typename CallbackType,
-              typename traits =
-                  FunctionTraits<typename std::decay<CallbackType>::type>>
-    typename std::enable_if<traits::isSqlCallback, self>::type &operator>>(
-        CallbackType &&callback)
-    {
-        callbackHolder_ = std::shared_ptr<CallbackHolderBase>(
-            new CallbackHolder<typename std::decay<CallbackType>::type>(
-                std::forward<CallbackType>(callback)));
-        return *this;
+        if constexpr (traits::isExceptCallback)
+        {
+            if constexpr (traits::isPtr)
+            {
+                // LOG_DEBUG << "ptr callback";
+                isExceptionPtr_ = true;
+                exceptionPtrCallback_ = std::forward<CallbackType>(callback);
+                return *this;
+            }
+            else
+            {
+                isExceptionPtr_ = false;
+                exceptionCallback_ = std::forward<CallbackType>(callback);
+                return *this;
+            }
+        }
+        else if constexpr (traits::isSqlCallback)
+        {
+            callbackHolder_ = std::shared_ptr<CallbackHolderBase>(
+                new CallbackHolder<typename std::decay<CallbackType>::type>(
+                    std::forward<CallbackType>(callback)));
+            return *this;
+        }
     }
 
     template <typename T>
-    typename std::enable_if<
-        !std::is_same<typename std::remove_cv<
-                          typename std::remove_reference<T>::type>::type,
-                      trantor::Date>::value,
-        self &>::type
-    operator<<(T &&parameter)
+    self &operator<<(T &&parameter)
     {
+        using ParaType = std::remove_cv_t<std::remove_reference_t<T>>;
         ++parametersNumber_;
-        using ParaType = typename std::remove_cv<
-            typename std::remove_reference<T>::type>::type;
         std::shared_ptr<void> obj = std::make_shared<ParaType>(parameter);
         if (type_ == ClientType::PostgreSQL)
         {
@@ -482,12 +464,7 @@ class DROGON_EXPORT SqlBinder : public trantor::NonCopyable
 
     self &operator<<(std::string &&str);
 
-    self &operator<<(trantor::Date &&date)
-    {
-        return operator<<(date.toDbStringLocal());
-    }
-
-    self &operator<<(const trantor::Date &date)
+    self &operator<<(trantor::Date date)
     {
         return operator<<(date.toDbStringLocal());
     }

trantor

@@ -1 +1 @@
-Subproject commit 624fc083076d7da88b1fb1dca1669ff48168a3ce
+Subproject commit d596221dd13a27ae86a637dba82154d0c5f96331