“const”是指“const”。修改 [英] The "const" modifier
问题描述
使用const的意义究竟是什么？一个函数之前的修饰符
声明？实际上，你可以在三个地方使用它。例如，请看
查看以下函数声明（来自介绍性书籍
Absolute C ++，作者：W。Savitch，第315页）
class Money
{
Money（）;
const Money运算符+（const Money& amount2）const;
私人：
int美元;
int美分;
}
我没有复制整个代码（还有更多的成员函数），但
这应该足以满足这个问题了。
const的含义在参数amount2之前对我来说很明显;
const就在分号发出信号之前，如果我做对了，那么函数可能不会改变调用对象。但是第一个
" const"
干杯，
马蒂亚斯
-
发送电子邮件至Anweisung in der Adresse befolgen
What exactly is the sense of using a "const" modifier before a function
declaration? Actually, you can use it in three places. For instance, take a
look at the following function declaration (from the introductory book
"Absolute C++" by W. Savitch, p. 315)
class Money
{
Money();
const Money operator + (const Money& amount2) const;
private:
int dollars;
int cents;
}
I didn''t copy the whole code (there are many more member functions), but
this should suffice for the question.
The meaning of the "const" before the parameter "amount2" is obvious to me;
the "const" just before the semicolon signals that the function may not
change the calling object if I got it right. But what about the first
"const"?
Cheers,
Matthias
--
Für emails Anweisung in der Adresse befolgen
推荐答案
Der Andere写道：
Der Andere wrote:
使用const的意义究竟是什么？一个函数
声明之前的修饰符？实际上，你可以在三个地方使用它。例如，看看下面的函数声明（来自W. Savitch的介绍书
Absolute C ++，第315页）
类金钱
金钱（）;
const金钱算子+（const Money& amount2）const;
私人：
int dollar;
int cents;
}
我没有复制整个代码（还有更多的成员函数），但
这应该足以满足这个问题了。
const的含义在参数amount2之前对我来说很明显;
const就在分号发出信号之前，如果我做对了，函数可能不会改变调用对象。但是第一个
const怎么样？
干杯，
马蒂亚斯
-
Für发送电子邮件给Anweisung in der Adresse befolgen
What exactly is the sense of using a "const" modifier before a function
declaration? Actually, you can use it in three places. For instance, take a
look at the following function declaration (from the introductory book
"Absolute C++" by W. Savitch, p. 315)
class Money
{
Money();
const Money operator + (const Money& amount2) const;
private:
int dollars;
int cents;
}
I didn''t copy the whole code (there are many more member functions), but
this should suffice for the question.
The meaning of the "const" before the parameter "amount2" is obvious to me;
the "const" just before the semicolon signals that the function may not
change the calling object if I got it right. But what about the first
"const"?
Cheers,
Matthias
--
Für emails Anweisung in der Adresse befolgen
这些问题在C ++ FAQ中讨论：
http://www.parashift.com/c++-faq-lit....html#faq-29.6
http：//www.parashift .com / c ++ - faq-lit ... rrectness.html
在发布前搜索常见问题总是一个好主意。
一个也应该搜索新闻组。
-
托马斯马修斯
C ++新闻组欢迎辞：
http://www.slack.net/~shiva/welcome。 txt
C ++常见问题： http://www.parashift.com/c++-faq-lite
C常见问题： http://www.eskimo.com/~scs/c-faq/top.html
alt.comp.lang.learn.c-c ++ faq：
http://www.raos.demon.uk/acllc-c++/faq.html
其他网站：
< a rel =nofollowhref =http://www.josuttis.comtarget =_ blank> http://www.josuttis.com - C ++ STL图书馆书籍
http://www.sgi.com/tech/stl - 标准模板库
These issues are discussed in the C++ FAQ:
http://www.parashift.com/c++-faq-lit....html#faq-29.6
http://www.parashift.com/c++-faq-lit...rrectness.html
Searching the FAQ before posting is always an excellent idea.
One should also search the newsgroups too.
--
Thomas Matthews
C++ newsgroup welcome message:
http://www.slack.net/~shiva/welcome.txt
C++ Faq: http://www.parashift.com/c++-faq-lite
C Faq: http://www.eskimo.com/~scs/c-faq/top.html
alt.comp.lang.learn.c-c++ faq:
http://www.raos.demon.uk/acllc-c++/faq.html
Other sites:
http://www.josuttis.com -- C++ STL Library book
http://www.sgi.com/tech/stl -- Standard Template Library
Der Andere写道：
Der Andere wrote:
使用const的意义究竟是什么？一个函数
声明之前的修饰符？实际上，你可以在三个地方使用它。例如，看看下面的函数声明（来自W. Savitch的介绍书
Absolute C ++，第315页）
类金钱
金钱（）;
const金钱算子+（const Money& amount2）const;
私人：
int dollar;
int cents;
}
我没有复制整个代码（还有更多的成员函数），但
这应该足以满足这个问题了。
const的含义在参数amount2之前对我来说很明显;
const就在分号发出信号之前，如果我做对了，函数可能不会改变调用对象。但是第一个
const呢？
What exactly is the sense of using a "const" modifier before a function
declaration? Actually, you can use it in three places. For instance, take a
look at the following function declaration (from the introductory book
"Absolute C++" by W. Savitch, p. 315)
class Money
{
Money();
const Money operator + (const Money& amount2) const;
private:
int dollars;
int cents;
}
I didn''t copy the whole code (there are many more member functions), but
this should suffice for the question.
The meaning of the "const" before the parameter "amount2" is obvious to me;
the "const" just before the semicolon signals that the function may not
change the calling object if I got it right. But what about the first
"const"?
这意味着返回的临时对象是const。这一段时间我发布了一个关于
的帖子：
http://groups.google.com/groups?thre...733r%404ax.com
很遗憾它并没有产生太多的讨论。那个帖子是由GotW＃6提示的
，这里：
http://www.gotw.ca/gotw/006.htm
这可能对您有所帮助。
-Kevin
-
我的电子邮件地址有效，但会定期更改。
联系我请使用最近发布的地址。
It means the returned temporary object is const. I posted a thread about
this a while back:
http://groups.google.com/groups?thre...733r%404ax.com
Unfortunately it didn''t generate much discussion. That thread was
prompted by GotW #6, here:
http://www.gotw.ca/gotw/006.htm
Which may be enlightening for you.
-Kevin
--
My email address is valid, but changes periodically.
To contact me please use the address from a recent posting.
Thomas Matthews< Th ********************* ****@sbcglobal.net>写道：
Thomas Matthews <Th*************************@sbcglobal.net> wrote:
Der Andere写道：
Der Andere wrote:
使用const的意义究竟是什么？一个函数
声明之前的修饰符？实际上，你可以在三个地方使用它。例如，看看下面的函数声明（来自W. Savitch的介绍书
Absolute C ++，第315页）
类金钱
金钱（）;
const金钱算子+（const Money& amount2）const;
私人：
int dollar;
int cents;
}
我没有复制整个代码（还有更多的成员函数），但
这应该足以满足这个问题了。
const的含义在参数amount2之前对我来说很明显;
const就在分号发出信号之前，如果我做对了，函数可能不会改变调用对象。但是第一个
const呢？
What exactly is the sense of using a "const" modifier before a function
declaration? Actually, you can use it in three places. For instance, take a
look at the following function declaration (from the introductory book
"Absolute C++" by W. Savitch, p. 315)
class Money
{
Money();
const Money operator + (const Money& amount2) const;
private:
int dollars;
int cents;
}
I didn''t copy the whole code (there are many more member functions), but
this should suffice for the question.
The meaning of the "const" before the parameter "amount2" is obvious to me;
the "const" just before the semicolon signals that the function may not
change the calling object if I got it right. But what about the first
"const"?
这些问题在C ++ FAQ中讨论过：
http://www.parashift.com/c++-faq-lit....html# faq-29.6
http ：//www.parashift.com/c++-faq-lit...rrectness.html
在发布前搜索常见问题总是一个好主意。
还应该也可以搜索新闻组。
These issues are discussed in the C++ FAQ:
http://www.parashift.com/c++-faq-lit....html#faq-29.6
http://www.parashift.com/c++-faq-lit...rrectness.html
Searching the FAQ before posting is always an excellent idea.
One should also search the newsgroups too.
我在FAQ中没有看到他的问题在哪里被回答...
I don''t see where his question is answered in the FAQ...
这篇关于“const”是指“const”。修改的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
