mem.cpp

Thinking in C++, 2nd Edition, Volume 2. 英文doc版 每章源代码

//: C07:Mem.cpp {O}
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 2000
// Copyright notice in Copyright.txt
#include "Mem.h"
#include <cstring>
using namespace std;

Mem::Mem() { mem = 0; size = 0; }

Mem::Mem(int sz) {
  mem = 0;
  size = 0;
  ensureMinSize(sz); 
}

Mem::~Mem() { delete []mem; }

int Mem::msize() { return size; }

void Mem::ensureMinSize(int minSize) {
  if(size < minSize) {
    byte* newmem = new byte[minSize];
    memset(newmem + size, 0, minSize - size);
    memcpy(newmem, mem, size);
    delete []mem;
    mem = newmem;
    size = minSize;
  }
}

byte* Mem::pointer() { return mem; }

byte* Mem::pointer(int minSize) {
  ensureMinSize(minSize);
  return mem; 
} ///:~