implemented hooks

.gitignore

@@ -1,3 +1,4 @@
 /bin/*
 *.report
 /ftb
+vgcore.*

hooks.hpp

@@ -0,0 +1,84 @@
+#pragma once
+#include "./arraylist.hpp"
+
+// For std::decay
+#include <type_traits>
+
+template<typename>
+struct TransientFunction; // intentionally not defined
+
+template<typename R, typename ...Args>
+struct TransientFunction<R(Args...)>
+{
+    using Dispatcher = R(*)(void*, Args...);
+
+    Dispatcher m_Dispatcher; // A pointer to the static function that will call the
+    // wrapped invokable object
+    void* m_Target;          // A pointer to the invokable object
+
+    // Dispatch() is instantiated by the TransientFunction constructor,
+    // which will store a pointer to the function in m_Dispatcher.
+    template<typename S>
+    static R Dispatch(void* target, Args... args)
+        {
+            return (*(S*)target)(args...);
+        }
+
+    template<typename T>
+    TransientFunction(T&& target)
+        : m_Dispatcher(&Dispatch<typename std::decay<T>::type>)
+        , m_Target(&target)
+        {
+        }
+
+    // Specialize for reference-to-function, to ensure that a valid pointer is
+    // stored.
+    using TargetFunctionRef = R(Args...);
+    TransientFunction(TargetFunctionRef target)
+        : m_Dispatcher(Dispatch<TargetFunctionRef>)
+        {
+            static_assert(sizeof(void*) == sizeof target,
+                          "It will not be possible to pass functions by reference on this platform. "
+                          "Please use explicit function pointers i.e. foo(target) -> foo(&target)");
+            m_Target = (void*)target;
+        }
+
+    R operator()(Args... args) const
+        {
+            return m_Dispatcher(m_Target, args...);
+        }
+};
+
+
+struct Hook : Array_List<TransientFunction<void()>> {
+    Hook() {
+        alloc();
+    }
+    ~Hook () {
+        dealloc();
+    }
+    void operator<<(TransientFunction<void()> f) {
+        // FIXME(Felix): Why can I not call Array_List::append here??? Hallo?
+        if (next_index == length) {
+            length *= 2;
+            data = (TransientFunction<void()>*)realloc(data, length * sizeof(TransientFunction<void()>));
+        }
+        data[next_index] = f;
+        next_index++;
+    }
+    void operator()() {
+        while(next_index --> 0) {
+            fflush(stdout);
+            data[next_index]();
+        }
+        next_index = 0;
+    }
+};
+
+struct __System_Shutdown_Hook : Hook {
+    void operator()() = delete;
+    ~__System_Shutdown_Hook() {
+        Hook::operator()();
+        dealloc();
+    }
+} system_shutdown_hook;

test.cpp

@@ -1,33 +1,26 @@
 #define _CRT_SECURE_NO_WARNINGS
 #include <stdio.h>
 
-#include "bucket_allocator.hpp"
+#include "./hooks.hpp"
 
+Hook h;
 int main(int argc, char* argv[]) {
-    Bucket_Allocator<int> ba(2, 1);
-
-    int* a = ba.allocate();
-    *a = 1;
-    ba.free_object(a);
-
-    int* b = ba.allocate();
-    *b = 2;
-
-    int* c = ba.allocate();
-    *c = 3;
-
-    int* d = ba.allocate();
-    *d = 4;
-
-    int* e = ba.allocate();
-    *e = 5;
-
-    int* f = ba.allocate();
-    *f = 6;
-
-    ba.for_each([](int* i){
-        printf("%d\n", *i);
-    });
+    printf("Hello world");
+    system_shutdown_hook << [] {
+        printf("Goodbye world\n");
+    };
+
+    h << []{
+        printf("Hallo1");
+    };
+    h << [] {
+       printf("Hallo2");
+    };
+
+    h << [] {
+        printf("Hallo3");
+    };
+    h();
 
     return 0;
 }