Re: Array size

From:
"Daniel T." <daniel_t@earthlink.net>
Newsgroups:
comp.lang.c++
Date:
Mon, 18 Feb 2008 21:36:10 -0500
Message-ID:
<daniel_t-208E9B.21361018022008@earthlink.vsrv-sjc.supernews.net>
"Jim Langston" <tazmaster@rocketmail.com> wrote:

Pavan wrote:

But what I need is I have a function like this

bool f(std::vector vec)
{

  int arr[vec.size()];
  ......
  ......
  .....
}

In the above I have a function that will create a array based on the
size of vector argument passed
to it. So I wanted to know is it ok to do like that. Also is it
allowed in VC++(windows) also?


As stated, it is not currently a part of the C++ standard. But my question
is why? Why do you want to create a variable lenght array as shown when you
can use a vector? What is wrong with:

std::vector<int> arr( vec.size() );

How does that not serve your purpose?

You can use that anywhere you can use an array of int although you need to
go an extra step when getting a pointer to the first element. With the
array you would use
arr
with the vector it would be
&arr[0]

&arr[0] should be an int* which should be usable where you would need either
an int * or int []


And also note that since he is passing the vector in by value, he
probably doesn't need to make yet another copy anyway.

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