Re: Using Iterator in Queue

From:
 James Kanze <james.kanze@gmail.com>
Newsgroups:
comp.lang.c++
Date:
Sun, 14 Oct 2007 07:48:58 -0700
Message-ID:
<1192373338.152992.52980@q5g2000prf.googlegroups.com>
On Oct 12, 5:42 pm, Donos <dongu...@gmail.com> wrote:

But still i can use a Queue to push data into it, right?
ie; std::queue<unsigned char> m_Queue;

I tried declaring the Iterator as ,

std::deque<unsigned char>::iterator m_Itr;


Why?

 then,

m_Itr = m_Queue.front(); // ERROR C2679

And this gives an error.

error C2679: binary '=' : no operator found which takes a right-hand
operand of type 'unsigned char' (or there is no acceptable conversion)


Queues are meant for queueing, not iterating. You can't get an
iterator into a queue, and if you need one, you shouldn't be
using a queue. And since there are no iterators for a queue,
you can't declare one.

What's wrong with simply:

    unsigned char ch = m_Queue.front() ;

?

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