编程交流与学习--Effective C++学习之"内存管理条款5"

最新推荐文章于 2025-08-15 18:53:39 发布

原创最新推荐文章于 2025-08-15 18:53:39 发布 · 842 阅读

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#c++ #编程 #delete #iostream #struct #编译器

本文通过一系列测试代码展示了在C++中使用new和delete操作符时需要注意的细节，特别是new和delete配对使用的正确方式及其重要性。

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条款5：对应的new和delete要采用相同的形式

为什么呢？还是看测试代码吧。原理是什么，作者似乎也没说。希望写过c++编译器的高手解释一下。

#include <iostream>

struct Global
{
public:
static int g_iCount;
};
int Global::g_iCount = 0;

struct NewDeleteTest
{
public:
int i;
NewDeleteTest()
{
  i = ++Global::g_iCount;
  printf("NewDeleteTest() /t:%d/n", i);
}
~NewDeleteTest()
{
  printf("~NewDeleteTest()/t:%d/n", i);
}
};

int main(void)
{
printf("new delete test/n");
NewDeleteTest *p1 = new NewDeleteTest;
try
{
delete p1;
}
catch(...)
{
printf("error: new delete/n");
}
p1 = NULL;Global::g_iCount = 0;
printf("/n/n");

printf("new delete[] test/n");
p1 = new NewDeleteTest;
try
{
delete [] p1;
}
catch(...)
{
printf("error: new delete[]/n");
}
p1 = NULL;Global::g_iCount = 0;
printf("/n/n");

printf("new[] delete test/n");
p1 = new NewDeleteTest[2];
try
{
delete p1;
}
catch(...)
{
printf("error: new[] delete/n");
}
p1 = NULL;Global::g_iCount = 0;
printf("/n/n");

printf("new[] delete[] test/n");
p1 = new NewDeleteTest[2];
try
{
delete [] p1;
}
catch(...)
{
printf("error: new[] delete[]/n");
}
p1 = NULL;Global::g_iCount = 0;
printf("/n/n");

return 0;
}