how to find the first iterator that not equals to some specifiedvalue?

[Leo jay]

dear all,

i know i can use std::find to find specified value in an iterator
range,
i'd like to know is there any way to find the first value that not
equals to the specified value?
just like string::find_fi rst_not_of,
or do i have to write a for loop and check manually?

thanks in advance.

[Barry]

Leo jay wrote:

dear all,

i know i can use std::find to find specified value in an iterator
range,
i'd like to know is there any way to find the first value that not
equals to the specified value?
just like string::find_fi rst_not_of,
or do i have to write a for loop and check manually?

thanks in advance.

find_if: the predicate version of find

bool not_equal_to_1( int i) {
return i != 1;
}

void foo(std::vector <intconst& V) {
std::vector<int >::const_iterat or pos =
std::find_if(V. begin(), V.end(), not_equal_to_1) ;
}

if you borrowing Boost.Lambda, it could be much simpler.

std::find_if(V. begin(), V.end(), _1 != 1);

--
Thanks
Barry

[William Xu]

Leo jay <Py***********@ gmail.comwrites :

i know i can use std::find to find specified value in an iterator
range,
i'd like to know is there any way to find the first value that not
equals to the specified value?
just like string::find_fi rst_not_of,
or do i have to write a for loop and check manually?

Try std::find_if.

--
William

http://williamxu.net9.org

[Salt_Peter]

On Jan 16, 10:20 pm, Leo jay <Python.Leo...@ gmail.comwrote:

dear all,

i know i can use std::find to find specified value in an iterator
range,
i'd like to know is there any way to find the first value that not
equals to the specified value?
just like string::find_fi rst_not_of,
or do i have to write a for loop and check manually?

thanks in advance.

std::find_if and std::not_equal_ to should do nicely.

assuming a vector of char:

#include <vector>
#include <algorithm // find_if
#include <functional // bind1st, not_equal_to

int main()
{
...
std::vector<cha r>::const_itera tor it
= std::find_if( vc.begin(),
vc.end(),
std::bind1st (std::not_equal _to<char>(),
'a') );
}

[Leo jay]

On Jan 17, 12:46 pm, Salt_Peter <pj_h...@yahoo. comwrote:

On Jan 16, 10:20 pm, Leo jay <Python.Leo...@ gmail.comwrote:

dear all,

i know i can use std::find to find specified value in an iterator
range,
i'd like to know is there any way to find the first value that not
equals to the specified value?
just like string::find_fi rst_not_of,
or do i have to write a for loop and check manually?

thanks in advance.

std::find_if and std::not_equal_ to should do nicely.

assuming a vector of char:

#include <vector>
#include <algorithm // find_if
#include <functional // bind1st, not_equal_to

int main()
{
...
std::vector<cha r>::const_itera tor it
= std::find_if( vc.begin(),
vc.end(),
std::bind1st (std::not_equal _to<char>(),
'a') );

}

thanks, that's what i'm looking for.