C ++中的动态类类型

Question

I'm writing a memory manager in C++ - that is, a class that allocates a lot of bytes from the heap, and then has allocate and deallocate functions for my program to use.

void* allocate(int size);
void deallocate(void*, int size);

This works fine, but what I don't like about it is that I need to do this to use it:

CClass* myobject = (CClass*) manager->allocate(sizeof(CClass));

So me question is, is there a way to pass the class type to the functions rather than using void pointers? This would remove the need for casting and the sizeof call, and it may also remove the need to pass the object size to the deallocate function.

Does anyone know of a better way I could be doing this?

Answer 1

You could use template functions.

Simplified example:

#include <string>
#include <iostream>
using namespace std;

template<typename T>
T* allocate() {
  return (T*) malloc(sizeof(T));
}

int main() {
  int *s = allocate<int>();
  *s = 42;
  return *s;
}

Answer 2

您可以为任何特定的用户定义类型重载新的运算符，并删除运算符，以便这些运算符使用您的分配器而不是默认的堆分配器。