cpp template application library (#232)

lib/callback-connector/callback-connector.h

@@ -0,0 +1,99 @@
+#ifndef CALLBACKCONNECTOR_H
+#define CALLBACKCONNECTOR_H
+#include <functional>
+namespace cbc {
+namespace Details {
+
+template <std::size_t Tag, typename T, typename Ret, typename... Args> class FuncMemberWrapper {
+public:
+    FuncMemberWrapper() = delete;
+    using member_fun_t = Ret (T::*)(Args...);
+    using const_member_fun_t = Ret (T::*)(Args...) const;
+    static auto instantiate(T* t, member_fun_t ptr) {
+        obj = t;
+        member = ptr;
+        return MetaCall;
+    }
+
+    static auto instantiate(T* t, const_member_fun_t ptr) {
+        obj = t;
+        const_member = ptr;
+        return ConstMetaCall;
+    }
+
+private:
+    static auto MetaCall(Args... args) {
+        return (*obj.*member)(args...);
+    }
+    static auto ConstMetaCall(Args... args) {
+        return (*obj.*const_member)(args...);
+    }
+    static T* obj;
+    static member_fun_t member;
+    static const_member_fun_t const_member;
+};
+template <std::size_t Tag, typename T, typename Ret, typename... Args>
+T* FuncMemberWrapper<Tag, T, Ret, Args...>::obj{};
+
+template <std::size_t Tag, typename T, typename Ret, typename... Args>
+typename FuncMemberWrapper<Tag, T, Ret, Args...>::member_fun_t
+    FuncMemberWrapper<Tag, T, Ret, Args...>::member{};
+
+template <std::size_t Tag, typename T, typename Ret, typename... Args>
+typename FuncMemberWrapper<Tag, T, Ret, Args...>::const_member_fun_t
+    FuncMemberWrapper<Tag, T, Ret, Args...>::const_member{};
+
+template <typename Functor, typename Ret, typename... Args> struct FunctorWrapper {
+public:
+    static std::function<Ret(Args...)> functor;
+    static auto instatiate(Functor fn) {
+        functor = std::move(fn);
+        return MetaCall;
+    }
+
+private:
+    static auto MetaCall(Args... args) {
+        return functor(args...);
+    }
+};
+
+template <typename Functor, typename Ret, typename... Args>
+std::function<Ret(Args...)> FunctorWrapper<Functor, Ret, Args...>::functor;
+
+template <typename Functor, typename Ret, typename T, typename... Args>
+auto deducer(Functor obj, Ret (T::*)(Args...) const) {
+    return FunctorWrapper<Functor, Ret, Args...>::instatiate(std::move(obj));
+}
+
+template <typename Functor, typename Ret, typename T, typename... Args>
+auto deducer(Functor obj, Ret (T::*)(Args...)) {
+    return FunctorWrapper<Functor, Ret, Args...>::instatiate(std::move(obj));
+}
+
+template <std::size_t tag, typename T, typename Ret, typename... Args>
+auto const_instantiate(T* t, Ret (T::*ptr)(Args...) const) {
+    return FuncMemberWrapper<tag, T, Ret, Args...>::instantiate(t, ptr);
+}
+
+template <std::size_t tag, typename T, typename Func> auto const_instantiate(T* t, Func ptr) {
+    return const_instantiate(t, ptr);
+}
+
+} //end of Details scope
+
+template <std::size_t tag = 0, typename T, typename Ret, typename... Args>
+auto obtain_connector(T* t, Ret (T::*ptr)(Args...)) {
+    return Details::FuncMemberWrapper<tag, T, Ret, Args...>::instantiate(t, ptr);
+}
+
+template <std::size_t tag = 0, typename T, typename Ret, typename... Args>
+auto obtain_connector(T* t, Ret (T::*ptr)(Args...) const) {
+    return Details::FuncMemberWrapper<tag, T, Ret, Args...>::instantiate(t, ptr);
+}
+
+template <typename Functor> auto obtain_connector(Functor functor) {
+    return Details::deducer(std::move(functor), &Functor::operator());
+}
+} //end of cbc scope
+
+#endif // CALLBACKCONNECTOR_H