Re: [Boost-users] How to change a local variable in the if_thenalgorithm

Meryl Silverburgh wrote:

Hi,

I have a sorted int vector 'orgWidth'. I would like to save the save into a new int vector 'newWidth' if the value of the current element is 10% bigger than the previous one.

For example, orgWidth int vector : 300 366 729 769 781 1297 newWidth int vector: 300 366 729 1297

I know how to add the value to the newWidth vector using the if_then with boost. But my question is how can I update the value of the 'previousWidth' as I use for_each() algorithm.

I'm not sure if it's useful to you, but the boost::bind solution is to use a helper function: #include #include <algorithm> #include <iostream> #include <iterator> static bool above_ten_percent( int & last, int x ) { bool r = x > last * 1.1; last = x; return r; } int main() { int v[] = { 300, 366, 729, 769, 781, 1297 }; std::remove_copy_if( v, v + 6, std::ostream_iterator<int>( std::cout, " " ), !boost::bind( above_ten_percent, 0, _1 ) ); }