分配给指针的内存量 [英] amount of memory allocated to a pointer
问题描述
我怎么能知道有多少内存被阻止（或已被分配
指针）
考虑，
int * p = new int;
或
int * p = new int [100];
假设我不知道语句的右侧即
new int或new int [100]或new int [n]（其中n是在
运行时期间计算的）
（绝对sizeof（p）不会给我分配的内存金额
。）
i会有兴趣了解程序中各个指针所占用的内存量。我怎么可能实现这个？
有没有任何方法或标准例程来衡量内存的数量？
如果没有标准方法或惯例为什么会如此？
pratap写道：
我怎么能知道有多少内存被阻止（或已被分配
指针）
考虑，
int * p = new int;
或
int * p = new int [100];
这对我来说看起来不像。你的意思是发布到comp.lang.c ++？
假设我不知道语句的右侧即
new int或新的int [100]或new int [n]（其中n是在
运行时期间计算的）
（绝对sizeof（p）不会给我分配的内存量
。）
i有兴趣知道
各个指针占用的内存量在一个程序中。我怎么可能实现这个？
有没有任何方法或标准程序来衡量内存的数量？
不在C中，我不相信C ++有任何不同。
如果有没有标准的方法或惯例为什么会这样？
我有一位前同事曾经说他会回答什么和
怎么样问题，但不是为什么问题......
基本上，这种语言根本不会那样工作。
Mark Bluemel说：
pratap写道：
< snip>
< blockquote class =post_quotes>
>我有兴趣知道程序中各个指针占用的内存量。我怎么可能实现这个？
有没有任何方法或标准程序来衡量内存的数量？
不在C中，我不相信C ++有任何不同。
实际上，指针占用的内存量很容易确定。在引用的段落（上文）中，OP询问错误的
问题。他应该问的是，给定一个指向
动态分配内存的指针，有多少正确类型的对象可以存储在这样分配的内存中。答案非常简单：
当一个人首先分配这个内存时，一个人知道可以在其中存储多少个b $ b对象，所以所有人必须做的就是不要忘了。
< snip>
-
Richard Heathfield< http：// www .cpax.org.uk>
电子邮件：-www。 + rjh @
谷歌用户：< http://www.cpax.org.uk/prg/writings/googly.php>
Usenet是一个奇怪的放置" - dmr 1999年7月29日
9月12日下午2:50，Richard Heathfield< r ... @ see.sig.invalidwrote：
Mark Bluemel说：
pratap写道：
< ; snip>
i有兴趣了解
各个指针占用的内存量在一个程序中。我怎么可能实现这个？
有没有任何方法或标准程序来衡量内存的数量？
不在C中，我不相信C ++有任何不同。
实际上，指针占用的内存量很容易确定。在引用的段落（上文）中，OP询问错误的
问题。他应该问的是，给定一个指向
动态分配内存的指针，有多少正确类型的对象可以存储在这样分配的内存中。答案非常简单：
当一个人首先分配这个内存时，一个人知道可以在其中存储多少个b $ b对象，所以所有人必须做的就是不要忘了。
< snip>
-
Richard Heathfield< http：// www .cpax.org.uk>
电子邮件：-www。 + rjh @
谷歌用户：< http://www.cpax.org.uk/prg/writings/googly.php>
Usenet是一个奇怪的放置" - - 1999年7月29日
使用_msize（p）的另一种方式
这比记住更容易！ ！ - ）
how could i find out how much memory is blocked(or has been allocated
to a pointer)
consider,
int *p=new int;
or
int *p=new int[100];
suppose i dont know the right hand side of the statement i.e.
new int or new int[100] or new int[n] (where n is calculated during
runtime)
(definitely sizeof(p) would not give me the amount of memory
allocated.)
i would be interested in knowing the amount of memory taken up by the
respective pointers in a program. how could i possibly achieve this?
Are there any methods or standard routines to measure the amount of
memory?
If there are no standard methods or routines why would this be so ?
pratap wrote:how could i find out how much memory is blocked(or has been allocated
to a pointer)
consider,
int *p=new int;
or
int *p=new int[100];This doesn''t look like C to me. Did you mean to post to comp.lang.c++?
suppose i dont know the right hand side of the statement i.e.
new int or new int[100] or new int[n] (where n is calculated during
runtime)
(definitely sizeof(p) would not give me the amount of memory
allocated.)
i would be interested in knowing the amount of memory taken up by the
respective pointers in a program. how could i possibly achieve this?
Are there any methods or standard routines to measure the amount of
memory?Not in C and I don''t believe C++ is any different.
If there are no standard methods or routines why would this be so ?I had a former colleague who used to say that he would answer "what" and
"how" questions, but not "why" questions...
Basically, the language simply doesn''t work that way.
Mark Bluemel said:
pratap wrote:<snip>
>i would be interested in knowing the amount of memory taken up by the
respective pointers in a program. how could i possibly achieve this?
Are there any methods or standard routines to measure the amount of
memory?
Not in C and I don''t believe C++ is any different.Actually, the amount of memory taken up by a pointer is very easy to
determine. In the quoted paragraph (above) the OP asks the wrong
question. What he ought to be asking is how, given a pointer to
dynamically allocated memory, how many objects of the proper type can
be stored in the memory thus allocated. And the answer is very easy:
when one allocates this memory in the first place, one knows how many
objects can be stored therein, so all one has to do is Not Forget.
<snip>
--
Richard Heathfield <http://www.cpax.org.uk>
Email: -www. +rjh@
Google users: <http://www.cpax.org.uk/prg/writings/googly.php>
"Usenet is a strange place" - dmr 29 July 1999
On Sep 12, 2:50 pm, Richard Heathfield <r...@see.sig.invalidwrote:Mark Bluemel said:
pratap wrote:
<snip>
i would be interested in knowing the amount of memory taken up by the
respective pointers in a program. how could i possibly achieve this?
Are there any methods or standard routines to measure the amount of
memory?
Not in C and I don''t believe C++ is any different.
Actually, the amount of memory taken up by a pointer is very easy to
determine. In the quoted paragraph (above) the OP asks the wrong
question. What he ought to be asking is how, given a pointer to
dynamically allocated memory, how many objects of the proper type can
be stored in the memory thus allocated. And the answer is very easy:
when one allocates this memory in the first place, one knows how many
objects can be stored therein, so all one has to do is Not Forget.
<snip>
--
Richard Heathfield <http://www.cpax.org.uk>
Email: -www. +rjh@
Google users: <http://www.cpax.org.uk/prg/writings/googly.php>
"Usenet is a strange place" - dmr 29 July 1999one more way is using _msize(p)
this is even more easier than remembering! !-)
这篇关于分配给指针的内存量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！
