From cba6f2ee89389f707ce1a49cf5a31a732c27d0a6 Mon Sep 17 00:00:00 2001
From: Jan Travnicek <Jan.Travnicek@fit.cvut.cz>
Date: Sat, 1 Mar 2014 08:12:53 +0100
Subject: [PATCH] working variant type
---
alib/src/std/type_traits.hpp | 28 +++++++++++++++++++++++
alib/src/std/variant.hpp | 43 ++++++++++++++++++++++++++----------
2 files changed, 59 insertions(+), 12 deletions(-)
create mode 100644 alib/src/std/type_traits.hpp
diff --git a/alib/src/std/type_traits.hpp b/alib/src/std/type_traits.hpp
new file mode 100644
index 0000000000..1ee68e2268
--- /dev/null
+++ b/alib/src/std/type_traits.hpp
@@ -0,0 +1,28 @@
+#ifndef TYPE_TRAITS_HPP_
+#define TYPE_TRAITS_HPP_
+
+#include <type_traits>
+
+namespace std {
+ template <typename T>
+ struct is_base_of<T, T> {
+ static const bool value = true;
+ };
+
+ template <typename T, typename... Ts>
+ struct is_base_of_any;
+
+ template <typename T, typename F>
+ struct is_base_of_any<T, F>
+ {
+ static const bool value = is_base_of<T, F>::value;
+ };
+
+ template <typename T, typename F, typename... Ts>
+ struct is_base_of_any<T, F, Ts...>
+ {
+ static const bool value = is_base_of<T, F>::value || is_base_of_any<T, Ts...>::value;
+ };
+}
+
+#endif
diff --git a/alib/src/std/variant.hpp b/alib/src/std/variant.hpp
index 1e091c6e0c..0ea1d040d6 100644
--- a/alib/src/std/variant.hpp
+++ b/alib/src/std/variant.hpp
@@ -5,10 +5,13 @@
* Modified: Jan Travnicek
*/
+#ifndef VATIANT_HPP_
+#define VATIANT_HPP_
+
#include <iostream>
#include <utility>
#include <typeinfo>
-#include <type_traits>
+#include "type_traits.hpp"
#include <string>
template <size_t arg1, size_t ... others>
@@ -42,10 +45,11 @@ struct variant_helper<F, Ts...> {
inline static void move(size_t old_t, void * old_v, void * new_v)
{
- if (old_t == typeid(F).hash_code())
+ if (old_t == typeid(F).hash_code()) {
new (new_v) F(std::move(*reinterpret_cast<F*>(old_v)));
- else
- variant_helper<Ts...>::move(old_t, old_v, new_v);
+ return true;
+ } else
+ return variant_helper<Ts...>::move(old_t, old_v, new_v);
}
inline static void copy(size_t old_t, const void * old_v, void * new_v)
@@ -79,7 +83,7 @@ struct variant_helper<F, Ts...> {
template<> struct variant_helper<> {
inline static void destroy(size_t id, void * data) { }
-inline static void move(size_t old_t, void * old_v, void * new_v) { }
+inline static bool move(size_t old_t, void * old_v, void * new_v) { return false; }
inline static void copy(size_t old_t, const void * old_v, void * new_v) { }
inline static bool compareEq(size_t this_t, const void * this_v, size_t other_t, const void * other_v) { return true; }
inline static bool compareLess(size_t this_t, const void * this_v, size_t other_t, const void * other_v) { return false; }
@@ -147,15 +151,28 @@ public:
return (type_id == typeid(T).hash_code());
}
- template<typename T, typename... Args>
- void set(Args&&... args)
+ template<typename T>
+ void set(T&& value)
{
- // First we destroy the current contents
- helper_t::destroy(type_id, &data);
- new (&data) T(std::forward<Args>(args)...);
- type_id = typeid(T).hash_code();
+ if(std::is_base_of_any<T, F, Ts...>::value) {
+ helper_t::destroy(type_id, &data);
+ new (&data) T(value);
+ type_id = typeid(T).hash_code();
+ } else
+ throw std::bad_cast();
}
-
+
+ template<typename T>
+ void set(T& value)
+ {
+ if(std::is_base_of_any<T, F, Ts...>::value) {
+ helper_t::destroy(type_id, &data);
+ new (&data) T(value);
+ type_id = typeid(T).hash_code();
+ } else
+ throw std::bad_cast();
+ }
+
template<typename T>
T& get()
{
@@ -170,3 +187,5 @@ public:
helper_t::destroy(type_id, &data);
}
};
+
+#endif
--
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