compare function for upper_bound / lower_bound

Question

I want to find the first item in a sorted vector that has a field less than some value x.
I need to supply a compare function that compares \'x\' with the internal value

Answer 1

Pass a lambda function to upper_bound

 float x;
 MyClass target;
 target.x_ = x;
 std::vector< MyClass >::iterator last = 
 std::upper_bound(myClass.begin(),myClass.end(),target, 
 [](const MyClass& a, const MyClass& b){return a.x_ < b.x_;});