cii-font-family: Verdana; mso-hansi-font-family: Verdana;">当c++cii-font-family: Verdana; mso-hansi-font-family: Verdana;">程序用new/class="tags" href="/tags/DELETE.html" title=delete>deletecii-font-family: Verdana; mso-hansi-font-family: Verdana;">运算符进行动态内存操作时࿰c;class="tags" href="/tags/CLASS.html" title=class>class="tags" href="/tags/BianYiQi.html" title=编译器>编译器为我们准备了两项class="tags" href="/tags/GongZuo.html" title=工作>工作。一是࿰c;调用全局内存分配函数 operator new() / operator class="tags" href="/tags/DELETE.html" title=delete>delete()cii-font-family: Verdana; mso-hansi-font-family: Verdana;">； cii-font-family: Verdana; mso-hansi-font-family: Verdana;">二是࿰c;调用 cii-font-family: Verdana; mso-hansi-font-family: Verdana;">“构造函数”和“析构函数”。

cii-font-family: Verdana; mso-hansi-font-family: Verdana;">下面举个例子说明：

color: blue; font-family: Verdana;" lang="EN-US">class="tags" href="/tags/CLASS.html" title=class>class TestType

color: blue; font-family: Verdana;" lang="EN-US">{

color: blue; font-family: Verdana;" lang="EN-US">public:

color: blue; font-family: Verdana;" lang="EN-US">TestType(){}

color: blue; font-family: Verdana;" lang="EN-US">~TestType(){}

color: blue; font-family: Verdana;" lang="EN-US">private:

color: blue; font-family: Verdana;" lang="EN-US">cerun: yes;">    int m_test;

color: blue; font-family: Verdana;" lang="EN-US">}

color: blue; font-family: Verdana;" lang="EN-US">TestType* ttData = new TestType();

cii-font-family: Verdana; mso-hansi-font-family: Verdana;">对于这里的newcii-font-family: Verdana; mso-hansi-font-family: Verdana;">分配内存࿰c;

（1）        cii-font-family: Verdana; mso-hansi-font-family: Verdana;">class="tags" href="/tags/CLASS.html" title=class>class="tags" href="/tags/BianYiQi.html" title=编译器>编译器调用operator new(sizeof(TestType)) cii-font-family: Verdana; mso-hansi-font-family: Verdana;">分配内存。

（2）        cii-font-family: Verdana; mso-hansi-font-family: Verdana;">class="tags" href="/tags/CLASS.html" title=class>class="tags" href="/tags/BianYiQi.html" title=编译器>编译器调用TestType ::TestType()cii-font-family: Verdana; mso-hansi-font-family: Verdana;">构造函数࿰c;构造对象。

color: #0000ff;">class="tags" href="/tags/DELETE.html" title=delete>delete ttData;

color: #0000ff;">ttData = Null;

cii-font-family: Verdana; mso-hansi-font-family: Verdana;">对于这里内存释放：

（1）        cii-font-family: Verdana; mso-hansi-font-family: Verdana;">class="tags" href="/tags/CLASS.html" title=class>class="tags" href="/tags/BianYiQi.html" title=编译器>编译器首先调用TestType ::~TestType()cii-font-family: Verdana; mso-hansi-font-family: Verdana;">࿰c;释放成员对象的资源。

（2）        cii-font-family: Verdana; mso-hansi-font-family: Verdana;">class="tags" href="/tags/CLASS.html" title=class>class="tags" href="/tags/BianYiQi.html" title=编译器>编译器调用 operator class="tags" href="/tags/DELETE.html" title=delete>delete(ttData)cii-font-family: Verdana; mso-hansi-font-family: Verdana;">释放内存。

cerun: yes;">     bbgcii-font-family: Verdana; mso-hansi-font-family: Verdana;">中的容器可以放置任何用户自定义类型࿰c;但是我们之前提供的color: fuchsia; font-family: Verdana;" lang="EN-US">simple_alloc cii-font-family: Verdana; mso-hansi-font-family: Verdana;">和color: fuchsia; font-family: Verdana;" lang="EN-US">alloc_poolcii-font-family: Verdana; mso-hansi-font-family: Verdana;">只有释放和分配内存࿰c;没有调用具体类的构造函数和析构函数。还好c++cii-font-family: Verdana; mso-hansi-font-family: Verdana;">提供了“定制newcii-font-family: Verdana; mso-hansi-font-family: Verdana;">特性”（喜欢c++cii-font-family: Verdana; mso-hansi-font-family: Verdana;">就是因为它的灵活）可以满足我们的目的࿰c;即在已有内存空间上调用具体类的构造函数。定制newcii-font-family: Verdana; mso-hansi-font-family: Verdana;">的语法如下：

color: blue; font-family: Verdana;" lang="EN-US">void * ttData = operator new(sizeof(TestType);

color: blue; font-family: Verdana;" lang="EN-US">new(ttData) TestType(); //cii-font-family: Verdana; mso-hansi-font-family: Verdana;">定制newcii-font-family: Verdana; mso-hansi-font-family: Verdana;">࿰c;在指针ttDatacii-font-family: Verdana; mso-hansi-font-family: Verdana;">所指内存上调用 TestTypecii-font-family: Verdana; mso-hansi-font-family: Verdana;">的构造函数

cii-font-family: Verdana; mso-hansi-font-family: Verdana;">   

cii-font-family: Verdana; mso-hansi-font-family: Verdana;">   对于内存空间的释放࿰c;我们则可以通过显式调用析构函数完成。如࿰c;

cii-font-family: Verdana; mso-hansi-font-family: Verdana;">color: #0000ff;">ttData->~TestType();

cii-font-family: Verdana; mso-hansi-font-family: Verdana;">具体源码：

c</a>ode" <a <a class="tags" href="/tags/C.html" title=c>c</a>lass="tags" href="/tags/CLASS.html" title=<a class="tags" href="/tags/C.html" title=c>c</a>lass><a class="tags" href="/tags/C.html" title=c>c</a>lass</a>="<a class="tags" href="/tags/C.html" title=c>c</a>-sharp">#ifndef _BBG_CONSTRUCT_H_ #define _BBG_CONSTRUCT_H_ #in<a class="tags" href="/tags/C.html" title=c>c</a>lude "../bbg_<a class="tags" href="/tags/C.html" title=c>c</a>ommon/bbg_<a class="tags" href="/tags/C.html" title=c>c</a>ommon.h" BEGIN_BBG template <<a <a class="tags" href="/tags/C.html" title=c>c</a>lass="tags" href="/tags/CLASS.html" title=<a class="tags" href="/tags/C.html" title=c>c</a>lass><a class="tags" href="/tags/C.html" title=c>c</a>lass</a> T , <a <a class="tags" href="/tags/C.html" title=c>c</a>lass="tags" href="/tags/CLASS.html" title=<a class="tags" href="/tags/C.html" title=c>c</a>lass><a class="tags" href="/tags/C.html" title=c>c</a>lass</a> V> inline void <a class="tags" href="/tags/C.html" title=c>c</a>onstru<a class="tags" href="/tags/C.html" title=c>c</a>t(T* p , <a class="tags" href="/tags/C.html" title=c>c</a>onst V& v) { new(p) T(v); } template <<a <a class="tags" href="/tags/C.html" title=c>c</a>lass="tags" href="/tags/CLASS.html" title=<a class="tags" href="/tags/C.html" title=c>c</a>lass><a class="tags" href="/tags/C.html" title=c>c</a>lass</a> T> inline void <a class="tags" href="/tags/C.html" title=c>c</a>onstru<a class="tags" href="/tags/C.html" title=c>c</a>t(T* p) { new(p) T(); } template <<a <a class="tags" href="/tags/C.html" title=c>c</a>lass="tags" href="/tags/CLASS.html" title=<a class="tags" href="/tags/C.html" title=c>c</a>lass><a class="tags" href="/tags/C.html" title=c>c</a>lass</a> T> inline void destroy(T* p) { p->~T(); } END_BBG #endif//_BBG_CONSTRUCT_H_