如何检测用户定义数组的读写访问权限？ [英] How to detect read or write access to a user defined array?
问题描述
嗨
假设我想创建一个只读项目数组
我重载[]运算符。如何检测我是否在阅读环境中被称为
foo =数组[23];
或者一个写上下文
数组[23] = foo;
据我记忆，这在C ++中是不可能的。
谢谢
Hi
Suppose that I want to create an array of read only items
I overload the [ ] operator. How can I detect if I am being called
within a read context
foo = Array[23];
or within a write context
Array[23] = foo;
As far as I remember, this is not possible in C++.
Thanks
推荐答案
" jacob navia" < ja *** @ jacob.remcomp.frwrote in message
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"jacob navia" <ja***@jacob.remcomp.frwrote in message
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嗨
假设我要创建一个只读项目数组
Hi
Suppose that I want to create an array of read only items
如果你想要一个只读数组，那你为什么不返回const引用呢？
Abdo Haji- Ali
程序员
In | Framez
If you want a read-only array, then why don''t you return a const reference?
Abdo Haji-Ali
Programmer
In|Framez
Abdo Haji-Ali写道：
Abdo Haji-Ali wrote:
" jacob navia" < ja *** @ jacob.remcomp.frwrote in message
news：46 *********************** @ news .orange.fr ...
"jacob navia" <ja***@jacob.remcomp.frwrote in message
news:46***********************@news.orange.fr...
>嗨
假设我要创建一个只读项目数组
>Hi
Suppose that I want to create an array of read only items
如果你想要一个只读数组，那你为什么不返回const引用呢？
Abdo Haji-Ali < br $>
程序员
In | Framez
If you want a read-only array, then why don''t you return a const reference?
Abdo Haji-Ali
Programmer
In|Framez
显然我需要初始化数组。
我想要一个只读数组的时间。
上下文：
我们在comp.lang上讨论过.c关于这一点，我只想知道
如果C ++中有可能在重载运算符中检测[]
如果我们被要求读取或者写作。
谢谢
Obviously I need to initialize the array.
I want a read only array MOST of the time.
Context:
We had a discussion in comp.lang.c about this, and I just want to know
if it is possible in C++ to detect within the overloaded operator [ ]
if we are being called for a read or for a write.
Thanks
" jacob navia" < ja *** @ jacob.remcomp.frwrote in message
news：46 *********************** @ news .orange.fr ...
"jacob navia" <ja***@jacob.remcomp.frwrote in message
news:46***********************@news.orange.fr...
我们在comp.lang.c中讨论了这个问题，我只是想知道
如果我们被调用读取或写入，如果可以在C ++中检测重载运算符[]
。
We had a discussion in comp.lang.c about this, and I just want to know
if it is possible in C++ to detect within the overloaded operator [ ]
if we are being called for a read or for a write.
那么，我认为你不能。基本上是阅读。操作并不总是
一读。请考虑以下事项：
int& foo = Array [0]; //假设Array是一个整数数组
在这种情况下，可以使用''foo''来读取：
int iValue = foo ;
或写作：
foo = iValue;
甚至没有引用原始用户数组。
Abdo Haji-Ali，
程序员
In | Framez
PS ：我会让这个索引器只读，并为
一次性提供其他功能。写。
Well then, I don''t think you can. Basically a "read" operation is not always
a read. Consider the following:
int& foo = Array[0]; // Assuming that Array is an integer array
In that case one can use ''foo'' for "reading":
int iValue = foo;
Or for writing:
foo = iValue;
Without even refering to the original user array.
Abdo Haji-Ali,
Programmer
In|Framez
PS: I would make this indexer read only and provide other function for
"one-time" write.
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