C++拾遺--定位new表達式
前言
new表達式,默認下把內存開闢到堆區。使用定位new表達式,可以在指定地址區域(棧區、堆區、靜態區)構造對象,這好比是把內存開闢到指定區域。
正文
定位new表達式的常見形式
- new(address) type;
- new(address) type(initializers);
- new(address) type[size];
- new(address) type[size]{braced initializer list};
示例代碼
#include <iostream>
using namespace std;
char addr1[100];
int main()
{
cout << "******定位new表達式演示***by David***" << endl;
char addr2[100];
char *addr3 = new char[100];
cout << "addr1 = " << (void*)addr1 << endl;
cout << "addr2 = " << (void*)addr2 << endl;
cout << "addr3 = " << (void*)addr3 << endl;
int *p = nullptr;
//把內存分配到靜態區
p = new(addr1)int;
*p = 1;
cout << (void*)p << " " << *p << endl;
//把內存分配到棧區
p = new(addr2)int;
*p = 2;
cout << (void*)p << " " << *p << endl;
//把內存分配到堆區
p = new(addr3)int;
*p = 3;
cout << (void*)p << " " << *p << endl;
cin.get();
return 0;
}
運行