MCOL-523 Add UDAF and UDAnF SDK

utils/common/any.hpp

@@ -0,0 +1,223 @@
+#pragma once
+/*
+ * (C) Copyright Christopher Diggins 2005-2011
+ * (C) Copyright Pablo Aguilar 2005
+ * (C) Copyright Kevlin Henney 2001
+ *
+ * Distributed under the Boost Software License, Version 1.0. (See
+ * accompanying file LICENSE_1_0.txt or copy at
+ * http://www.boost.org/LICENSE_1_0.txt
+ */
+
+#include <stdexcept>
+
+namespace static_any
+{
+namespace anyimpl
+{
+
+	struct bad_any_cast 
+	{
+	};
+
+	struct empty_any 
+	{
+	};
+
+	struct base_any_policy 
+	{
+		virtual void static_delete(void** x) = 0;
+		virtual void copy_from_value(void const* src, void** dest) = 0;
+		virtual void clone(void* const* src, void** dest) = 0;
+		virtual void move(void* const* src, void** dest) = 0;
+		virtual void* get_value(void** src) = 0;
+		virtual size_t get_size() = 0;
+	};
+
+	template<typename T>
+	struct typed_base_any_policy : base_any_policy
+	{
+		virtual size_t get_size() { return sizeof(T); } 
+	};
+
+	template<typename T>
+	struct small_any_policy : typed_base_any_policy<T>
+	{
+		virtual void static_delete(void** x) { }
+		virtual void copy_from_value(void const* src, void** dest)
+			{ new(dest) T(*reinterpret_cast<T const*>(src)); }
+		virtual void clone(void* const* src, void** dest) { *dest = *src; }
+		virtual void move(void* const* src, void** dest) { *dest = *src; }
+		virtual void* get_value(void** src) { return reinterpret_cast<void*>(src); }
+	};
+
+	template<typename T>
+	struct big_any_policy : typed_base_any_policy<T>
+	{
+		virtual void static_delete(void** x) { if (*x) 
+			delete(*reinterpret_cast<T**>(x)); *x = NULL; }
+		virtual void copy_from_value(void const* src, void** dest) { 
+		   *dest = new T(*reinterpret_cast<T const*>(src)); }
+		virtual void clone(void* const* src, void** dest) { 
+		   *dest = new T(**reinterpret_cast<T* const*>(src)); }
+		virtual void move(void* const* src, void** dest) { 
+		  (*reinterpret_cast<T**>(dest))->~T(); 
+		  **reinterpret_cast<T**>(dest) = **reinterpret_cast<T* const*>(src); }
+		virtual void* get_value(void** src) { return *src; }
+	};
+
+	template<typename T>
+	struct choose_policy 
+	{
+		typedef big_any_policy<T> type;
+	};
+
+	template<typename T> 
+	struct choose_policy<T*> 
+	{ 
+		typedef small_any_policy<T*> type; 
+	};
+
+	struct any;
+
+	/// Choosing the policy for an any type is illegal, but should never happen.
+	/// This is designed to throw a compiler error.
+	template<>
+	struct choose_policy<any>
+	{
+		typedef void type;
+	};
+
+	/// Specializations for small types.
+	#define SMALL_POLICY(TYPE) template<> struct \
+	   choose_policy<TYPE> { typedef small_any_policy<TYPE> type; };
+
+	SMALL_POLICY(char);
+	SMALL_POLICY(signed char);
+	SMALL_POLICY(unsigned char);
+	SMALL_POLICY(signed short);
+	SMALL_POLICY(unsigned short);
+	SMALL_POLICY(signed int);
+	SMALL_POLICY(unsigned int);
+	SMALL_POLICY(signed long);
+	SMALL_POLICY(unsigned long);
+	SMALL_POLICY(signed long long);
+	SMALL_POLICY(unsigned long long);
+	SMALL_POLICY(float);
+	SMALL_POLICY(double);
+	SMALL_POLICY(bool);
+	SMALL_POLICY(std::string);
+
+	#undef SMALL_POLICY
+
+	/// This function will return a different policy for each type. 
+	template<typename T>
+	base_any_policy* get_policy()
+	{
+		static typename choose_policy<T>::type policy;
+		return &policy;
+	};
+}
+
+class any
+{
+private:
+    // fields
+    anyimpl::base_any_policy* policy;
+    void* object;
+
+public:
+    /// Initializing constructor.
+    template <typename T>
+    any(const T& x) 
+        : policy(anyimpl::get_policy<anyimpl::empty_any>()), object(NULL) 
+    {
+        assign(x);
+    }       
+
+    /// Empty constructor. 
+    any() 
+        : policy(anyimpl::get_policy<anyimpl::empty_any>()), object(NULL) 
+    { }
+
+    /// Special initializing constructor for string literals. 
+    any(const char* x) 
+        : policy(anyimpl::get_policy<anyimpl::empty_any>()), object(NULL) 
+    { 
+        assign(x);
+    }
+
+    /// Copy constructor. 
+    any(const any& x) 
+        : policy(anyimpl::get_policy<anyimpl::empty_any>()), object(NULL)         
+    {            
+        assign(x);
+    }
+
+    /// Destructor. 
+    ~any() {
+        policy->static_delete(&object);
+    }
+
+    /// Assignment function from another any. 
+    any& assign(const any& x) {
+        reset();
+        policy = x.policy;
+        policy->clone(&x.object, &object);
+        return *this;
+    }
+
+    /// Assignment function. 
+    template <typename T>
+    any& assign(const T& x) {
+        reset();
+        policy = anyimpl::get_policy<T>();
+        policy->copy_from_value(&x, &object);
+        return *this;
+    }
+
+    /// Assignment operator.
+    template<typename T>
+    any& operator=(const T& x) {
+        return assign(x);
+    }
+
+    /// Assignment operator, specialed for literal strings. 
+    /// They have types like const char [6] which don't work as expected. 
+    any& operator=(const char* x) {
+        return assign(x);
+    }
+
+    /// Utility functions
+    any& swap(any& x) {
+        std::swap(policy, x.policy);
+        std::swap(object, x.object);
+        return *this;
+    }
+
+    /// Cast operator. You can only cast to the original type.
+    template<typename T>
+    T& cast() {
+        if (policy != anyimpl::get_policy<T>()) 
+            throw anyimpl::bad_any_cast();
+        T* r = reinterpret_cast<T*>(policy->get_value(&object)); 
+        return *r;
+    }
+
+    /// Returns true if the any contains no value. 
+    bool empty() const {
+        return policy == anyimpl::get_policy<anyimpl::empty_any>();
+    }
+
+    /// Frees any allocated memory, and sets the value to NULL.
+    void reset() {
+        policy->static_delete(&object);
+        policy = anyimpl::get_policy<anyimpl::empty_any>();
+    }
+
+    /// Returns true if the two types are the same. 
+    bool compatible(const any& x) const {
+        return policy == x.policy;
+    }
+};
+}