Re: [Boost-users] boost::lambda to replace a for loop

From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2008-07-29 16:22:23

AMDG

David Rodríguez Ibeas wrote:
> Ok, here's myquestion: What does exactly mean that std::find_if is not 
> allowed to change the sequence? How does the code. It is not changing 
> the vector in any way (just using a constant iterator) it is not even 
> modifying the contents of the vector. It is just calling a (possibly 
> not constant) method through a (constant) pointer. To me that is not 
> modifying the input sequence.
>
> Or is it more a general concern that they are not equivalent even if 
> in this case std::find_if could be used?

To be precise the standard states:

"The function object pred shall not apply any
non-constant function through the dereferenced iterator."

I presume that non-constant means anything that could make
pred(x) != pred(x) be true.

In Christ,
Steven Watanabe