一个c/c++函数调用栈的实现

函数调用栈的实现。可用于实现简单的脚本解释器。
声明:
#pragma once
const int BUFFERSIZE = 1024;
const int growfactor = 2;
// this stack is used as call stack.
class TStack{
private:
size_t size;   // the stack length
size_t pos;   // the stack top position   
char *buffer;  // the buffer

private:
void push(void* D, size_t bytecount);  // the implementation of push
void* pop(size_t bytecount);  // the implementation of pop
public:
TStack(size_t _size = BUFFERSIZE, size_t _pos = 0);  // initialize
TStack(const TStack& o);  // copy
TStack& operator=(const TStack& o);  // assignment
void pushInt(int i) { push(&i, sizeof(int)); }  // push an int
void pushLong(long l) { push(&l, sizeof(long)); }  // push a long
void pushfloat(double f) { push(&f, sizeof(f));}  // push  a double
void pushPointer(void* p){ push(p, sizeof(p)); }
// int 
int popInt() { return *(int *)pop(sizeof(int));}  // pop an int
long popLong() { return *(long *)pop(sizeof(long)); }  // pop an int    
double* popfloat() { return (double*)pop(sizeof(double)); }  // pop a double
void* popPointer() { return pop(sizeof(void*)) ; }
void clear() { pos = 0; }  
};
实现：
#include "stdafx.h"
#include "TStack.h"
#include "new.h"
void TStack::push( void* D, size_t bytecount )
{
// if memory is not enough
// if run under multithread envionment,
// a lock or critical section should be added
if (pos + bytecount > size)
{   
  size_t oldsize = size;
       size *= growfactor;   
  char *newbuffer = new char[size];
  memcpy(newbuffer, buffer, oldsize);
  delete buffer;
  buffer = newbuffer;   
}
memcpy(buffer+pos, D, bytecount);
pos += bytecount;
}
void* TStack::pop( size_t bytecount )
{
// need synchronization f