重载函数 [英] overloading a function
问题描述
我可以传递泛型吗？类指针作为函数的参数？
例如，说classA和B都是从Z派生的。
{
int iType = 1;
班级？ * pGeneric;
if（iType == 0）
pGeneric = new ClassA;
else
pGeneric = new ClassB;
OverloadedFunc（pGeneric）;
}
其中
OverloadedFunc（ClassA * pA）{}
OverloadedFunc（ClassA * pB）{}
或我必须这样做：
if（iType == 0）
{ClassA * pA = new ClassA;
OverloadedFunc（pB）; }
else
{ClassB * pB = new ClassB;
OverloadedFunc（pB）; }
谢谢
" Joe" ; < no*@work.com>在消息中写道
news：41 ********************** @ news-text.dial.pipex.com ...... < blockquote class =post_quotes>
我可以传递泛型吗？类指针作为函数的参数？
例如，说classA和B都是从Z派生的。
{
int iType = 1;
课程？ * pGeneric;
if（iType == 0）
pGeneric = new ClassA;
pGeneric = new ClassB;
OverloadedFunc （pGeneric）;
}
OverloadedFunc（ClassA * pA）{}
OverloadedFunc（ClassA * pB）{}
或者我必须这样做：
if（iType == 0）
{ClassA * pA = new ClassA;
OverloadedFunc（pB）; }
其他
{ClassB * pB = new ClassB;
OverloadedFunc（pB）; }
谢谢
为什么不使用基类？
void OverloadedFunc（ClassZ * pZ）{}
那是常见的事情。
john
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新闻：41 ********************** @ news-text.dial.pipex.com ...
我可以传递泛型吗？类指针作为函数的参数？
例如，说classA和B都是从Z派生的。
{
int iType = 1;
课程？ * pGeneric;
if（iType == 0）
pGeneric = new ClassA;
pGeneric = new ClassB;
OverloadedFunc （pGeneric）;
}
OverloadedFunc（ClassA * pA）{}
OverloadedFunc（ClassA * pB）{}
或者我必须这样做：
if（iType == 0）
{ClassA * pA = new ClassA;
OverloadedFunc（pB）; }
其他
{ClassB * pB = new ClassB;
OverloadedFunc（pB）; }
谢谢
为什么不使用基类？
void OverloadedFunc（ClassZ * pZ）{}
这将是通常的事情。
约翰
或者（我想我现在看到你要去的地方） make OverloadedFunc一个
ClassA，ClassB和ClassZ的虚拟成员函数，然后就可以写了
int iType = 1;
ClassZ * pGeneric;
if（iType == 0）
pGeneric = new ClassA;
else
pGeneric = new ClassB;
pGeneric-> OverloadedFunc（）;
如果那不是'' t出于某种原因，请使用dynamic_cast。
int iType = 1;
ClassZ * pGeneric;
if（iType == 0）
pGeneric = new ClassA;
else
pGeneric = new ClassB;
ClassA * pA;
ClassB * pB;
if（pA = dynamic_cast< ClassA *>（pGeneric））
Overl oadedFunc（pA）;
else if（pB = dynamic_cast< ClassB *>（pGeneric））
OverloadedFunc（pB）;
else
错误;
john
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新闻：41 ********************** @ news-text.dial.pipex.com ...
我可以传递泛型吗？类指针作为函数的参数？
< snip>
或者（我想我现在看到你要去的地方）make OverloadedFunc
aA类，ClassB和ClassZ的虚拟成员函数，那么你可以写一下iType = 1;
ClassZ * pGeneric;
if（ iType == 0）
pGeneric = new ClassA;
pGeneric = new ClassB;
pGeneric-> OverloadedFunc（）;
我觉得这有点乱，因为重载的功能已经是另一个类的b / b
的一部分了。
如果由于某种原因不行，请使用dynamic_cast。
int iType = 1;
ClassZ * pGeneric;
如果（iType == 0）
pGeneric = new ClassA;
pGeneric = new ClassB;
ClassA * pA;
ClassB * pB;
if（pA = dynamic_cast< ClassA *>（pGeneric））
OverloadedFunc（pA）;
else if（pB = dynamic_cast< ClassB *>（pGeneric））
OverloadedFunc （pB）;
错误;
看起来比我原来的更干净。
因此，您似乎无法定义通用。指示的类型
知道
它指向哪个类，所以当作为参数传递时，一个超载的
函数可以ID它的类型并称其正确版本。
Hi,
Can I pass a "generic" class pointer as an argument to a function?
For instance say classA and B are both derived from Z.
{
int iType =1;
Class? * pGeneric;
if(iType==0)
pGeneric= new ClassA;
else
pGeneric= new ClassB;
OverloadedFunc(pGeneric);
}
Where
OverloadedFunc( ClassA *pA){}
OverloadedFunc( ClassA *pB){}
or must I do:
if(iType==0)
{ ClassA *pA= new ClassA;
OverloadedFunc(pB); }
else
{ ClassB *pB= new ClassB;
OverloadedFunc(pB); }
Thanks
"Joe" <no*@work.com> wrote in message
news:41**********************@news-text.dial.pipex.com...Hi,
Can I pass a "generic" class pointer as an argument to a function?
For instance say classA and B are both derived from Z.
{
int iType =1;
Class? * pGeneric;
if(iType==0)
pGeneric= new ClassA;
else
pGeneric= new ClassB;
OverloadedFunc(pGeneric);
}
Where
OverloadedFunc( ClassA *pA){}
OverloadedFunc( ClassA *pB){}
or must I do:
if(iType==0)
{ ClassA *pA= new ClassA;
OverloadedFunc(pB); }
else
{ ClassB *pB= new ClassB;
OverloadedFunc(pB); }
Thanks
Why not use the base class?
void OverloadedFunc( ClassZ *pZ){}
That would be the usual thing to do.
john
"John Harrison" <jo*************@hotmail.com> wrote in message
news:2n***********@uni-berlin.de...
"Joe" <no*@work.com> wrote in message
news:41**********************@news-text.dial.pipex.com...Hi,
Can I pass a "generic" class pointer as an argument to a function?
For instance say classA and B are both derived from Z.
{
int iType =1;
Class? * pGeneric;
if(iType==0)
pGeneric= new ClassA;
else
pGeneric= new ClassB;
OverloadedFunc(pGeneric);
}
Where
OverloadedFunc( ClassA *pA){}
OverloadedFunc( ClassA *pB){}
or must I do:
if(iType==0)
{ ClassA *pA= new ClassA;
OverloadedFunc(pB); }
else
{ ClassB *pB= new ClassB;
OverloadedFunc(pB); }
Thanks
Why not use the base class?
void OverloadedFunc( ClassZ *pZ){}
That would be the usual thing to do.
john
Alternatively (I think I see where you are going now) make OverloadedFunc a
virtual member function of ClassA, ClassB and ClassZ, then you can write
int iType =1;
ClassZ * pGeneric;
if(iType==0)
pGeneric= new ClassA;
else
pGeneric= new ClassB;
pGeneric->OverloadedFunc();
And if that isn''t OK for some reason, use dynamic_cast.
int iType =1;
ClassZ * pGeneric;
if(iType==0)
pGeneric= new ClassA;
else
pGeneric= new ClassB;
ClassA * pA;
ClassB * pB;
if (pA = dynamic_cast<ClassA*>(pGeneric))
OverloadedFunc(pA);
else if (pB = dynamic_cast<ClassB*>(pGeneric))
OverloadedFunc(pB);
else
error;
john
"John Harrison" <jo*************@hotmail.com> wrote in message
news:2n***********@uni-berlin.de...
"John Harrison" <jo*************@hotmail.com> wrote in message
news:2n***********@uni-berlin.de...
"Joe" <no*@work.com> wrote in message
news:41**********************@news-text.dial.pipex.com...Hi,
Can I pass a "generic" class pointer as an argument to a function?
<snip>
Alternatively (I think I see where you are going now) make OverloadedFunc a virtual member function of ClassA, ClassB and ClassZ, then you can write
int iType =1;
ClassZ * pGeneric;
if(iType==0)
pGeneric= new ClassA;
else
pGeneric= new ClassB;
pGeneric->OverloadedFunc();
That would be a bit messy I think as the overloaded function is part of
another class already.
And if that isn''t OK for some reason, use dynamic_cast.
int iType =1;
ClassZ * pGeneric;
if(iType==0)
pGeneric= new ClassA;
else
pGeneric= new ClassB;
ClassA * pA;
ClassB * pB;
if (pA = dynamic_cast<ClassA*>(pGeneric))
OverloadedFunc(pA);
else if (pB = dynamic_cast<ClassB*>(pGeneric))
OverloadedFunc(pB);
else
error;
That doesn''t look any cleaner than my original.
So it appears that you can''t define a "generic" type of pointer which
"knows"
what class it points to, so that when passed as a parameter an overloaded
function can ID its type and call its correct version.
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