Answers for "std find"

vector.find()

#include <algorithm>
#include <vector>

if ( std::find(vec.begin(), vec.end(), item) != vec.end() )
   do_this();
else
   do_that();

c++ find with predicat

if(find_if(table.begin(), table.end(), [&new_id](const entry &arg) { 
                                           return arg.first == new_id; }) != ...)