将引用转换为 C++ 中的指针表示

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时间:2020-08-27 22:26:38  来源:igfitidea点击:

convert reference to pointer representation in C++

c++pointersreference

提问by Mark

Is there a way to "convert" a reference to pointer in c++? In example below, func2has already defined prototype and I can't change it, but funcis my API, and I'd like to either pass both parameters, or one (and second set to NULL) or neither (both set to NULL):

有没有办法在 C++ 中“转换”对指针的引用?在下面的示例中,func2已经定义了原型并且我无法更改它,但它func是我的 API,我想传递两个参数,或者传递一个(第二个设置为 NULL)或都不传递(都设置为 NULL):

void func2(some1 *p1, some2 *p2);

func(some1& obj, some2& obj2)
{
   func2(..);
}

回答by Chen

func2(&obj, &obj2);

func2(&obj, &obj2);

Use reference parameters like normal variables.

像普通变量一样使用引用参数。

回答by Jonathan Wood

Just get the address of the object.

只需获取对象的地址即可。

some1 *p = &obj;

Or in your case:

或者在你的情况下:

func2(&obj, &obj2);

回答by Umer Farooq

 func2(&obj, &obj2);

is what you should use.

是你应该使用的。

回答by Jarod42

In normal cases, you can simply use &:

在正常情况下,您可以简单地使用&

void func(some1& obj, some2& obj2)
{
    func2(&obj, &obj2);
}

but operator&might be overloaded, so std::addressof(since C++11) should be used for those cases:

operator&可能会重载,因此std::addressof(自 C++11 起)应用于这些情况:

void func(some1& obj, some2& obj2)
{
    func2(std::addressof(obj), std::addressof(obj2));
}

回答by Jarod42

For a clean design put all in a class (or use namespaces)

对于干净的设计,将所有内容放在一个类中(或使用命名空间)

class X {
   private:
   void func2(someA*, someB*);

   public:
   func(someA& a, someB& b) { func2(&a, &b); }
   func(someA& a) { func2(&a, 0); }
   func() { func2(0, 0); }
}