From 2c88d329b989b833dd8c00e21660f06fa6b64601 Mon Sep 17 00:00:00 2001
From: Avril <flanchan@cumallover.me>
Date: Fri, 11 Jun 2021 01:56:29 +0100
Subject: [PATCH] typed cow testing n stuff

---
 include/cow/typed.hpp | 51 +++++++++++++++++++++++--------------------
 src/test/main.cpp     |  7 ++++++
 2 files changed, 34 insertions(+), 24 deletions(-)

diff --git a/include/cow/typed.hpp b/include/cow/typed.hpp
index 34f9572..dedadd7 100644
--- a/include/cow/typed.hpp
+++ b/include/cow/typed.hpp
@@ -6,39 +6,42 @@
 template<typename T>
 struct TypedCow : private Cow, public _cow_util::Span<T> {
 	struct Fake;
-
-	inline TypedCow(size_t sz) : TypedCow(sz, T()) {}
+	friend class Fake;
+
+	TypedCow() = delete;
+	inline TypedCow(TypedCow<T>&& move) : Cow(std::move(move.super)) { /* Moves the shared_ptr. No need to move the elements. */ }
+	// protected: copy
+	
+	inline TypedCow(size_t sz) : Cow(sz * sizeof(T)) { init_copy(T()); }
+	inline TypedCow(size_t sz, const T& copy_from) : TypedCow(sz) { init_copy(copy_from); }
 	template<typename... Args>
-	inline TypedCow(size_t sz, Args&&... args) : TypedCow(sz, T(std::forward<Args>(args)...)) {}
+	inline TypedCow(size_t sz, Args&&... args) : TypedCow(sz) { init_copy( T(std::forward<Args>(args)...) ); }
 
-	inline TypedCow(TypedCow<T>&& move) : Cow(std::move(move.super)) {
-		unsigned char* bytes = this->as_bytes();
-		for(size_t i=0;i<size();i++)
-			new ((void*)(bytes + (sizeof(T)*i))) T(std::move(move[i]));
-	}
-	inline TypedCow(const TypedCow<T>& copy) : Cow(copy.super) {
-		unsigned char* bytes = this->as_bytes();
-		for(size_t i=0;i<size();i++)
-			new ((void*)(bytes + (sizeof(T)*i))) T(copy[i]);
-	}
-	inline ~TypedCow() {
-		unsigned char* bytes = this->as_bytes();
-		for(size_t i=0;i<size();i++)
-			reinterpret_cast<T*>(bytes + (sizeof(T)*i))->~T();
-	}
+	inline ~TypedCow() { uninit(); }
 
-	void* area() { return (*this).Cow::area(); }
-	const void* area() const { return (*this).Cow::area(); }
-	inline size_t size() const override { return (*this).Cow::size() / sizeof(T); }
+	inline void* area() { return Cow::area(); }
+	inline const void* area() const { return Cow::area(); }
+	inline size_t size() const override { return Cow::size() / sizeof(T); }
 
 	inline T& operator[](size_t i) { if (i>=size()) throw "idx"; else return *reinterpret_cast<T*>(this->as_bytes() + (sizeof(T) * i)); }
 	inline const T& operator[](size_t i) const { if (i>=size()) throw "idx"; else return *reinterpret_cast<const T*>(this->as_bytes() + (sizeof(T) * i)); }
 
-	private:
-	inline explicit TypedCow(size_t sz, const T& copy_from) : Cow(sz * sizeof(T)) {
+	protected:
+	// Should only be used for creating Fakes. Copies the refcounted pointer.
+	inline TypedCow(const TypedCow<T>& copy) : Cow(copy.super) {}
+
+	// UNSAFE: Placement-new's copys of `copy_from` into `0..size()` of this instance.
+	inline void init_copy(const T& copy_from) {
 		unsigned char* bytes = this->as_bytes();
-		for(size_t i=0;i<sz;i++)
+		for(size_t i=0;i<size();i++)
 			new ((void*)(bytes + (sizeof(T)*i))) T(copy_from);
+
+	}
+	// UNSAFE: Explicitly calls destructors of each element in this instance.
+	inline void uninit() {
+		unsigned char* bytes = this->as_bytes();
+		for(size_t i=0;i<size();i++)
+			reinterpret_cast<T*>(bytes + (sizeof(T)*i))->~T();
 	}
 };
 
diff --git a/src/test/main.cpp b/src/test/main.cpp
index 0dc4850..8df8991 100644
--- a/src/test/main.cpp
+++ b/src/test/main.cpp
@@ -169,6 +169,12 @@ void moving_cow(Cow moved)
 	read_fake(moved);
 }
 
+void typed_cow()
+{
+	TypedCow<int> tc(1024);
+	
+}
+
 int main()
 {
 	Cow _area(4000);
@@ -217,6 +223,7 @@ int main()
 	printf("First byte of: fake = %x\n", clone[0]);
 	read_fake(clone); //clone still functions because of refcount on origin.
 
+	typed_cow();
 	printf("Last error: %d, %s\n", cow_err(), *cow_err_msg(cow_err()));
 	try {
 		Cow should_fail(SIZE_MAX);