How to skip the first element of the vector and iterate from second using range based for loops [duplicate] - c++11

Question

I have a std::vector<std::string> v; (initialized). How can I use the range-for loop for accessing all elements except the first one (on index zero). For all elements:
for (const string & s: v)
process(s);
Instead of the v a range expression can be used. How can I write the range expression to skip the first element (or skip the first n elements)?
I know how to get the effect using v.begin() + 1 and using the classic loop. I am searching for the new, more readable, recommended alternative to do that. Possibly something similar to Python slicing? ...like:
for s in v[1:]:
process(s)

Answer 1

Until ranges make it into the standard library, you won't get any better than a vanilla for loop in plain C++ :
for(auto i = begin(v) + 1, e = end(v); i !=e; ++i)
// Do something with *i

Answer 2

Create a wrapper for which begin() and end() return the correct iterators and then you can use that as the second argument.
#include <iostream>
#include <vector>
template< typename Collection >
class FromNth
{
Collection& coll_;
size_t offset_;
public:
FromNth( Collection& coll, size_t offset )
: coll_( coll ), offset_( offset )
{
}
// will nicely resolve to const_iterator if necessary
auto begin() const -> decltype( coll_.begin() )
{ return coll_.begin() + offset_; }
auto end() const -> decltype( coll_.end() )
{ return coll_.end(); }
};
template< typename Collection >
FromNth<Collection> makeFromNth( Collection& collection, size_t offset )
{
return FromNth<Collection>( collection, offset );
}
template< typename Collection >
auto begin( const FromNth<Collection> & wrapper ) -> decltype( wrapper.begin() )
{
return wrapper.begin();
}
template< typename Collection >
auto end( const FromNth<Collection> & wrapper ) -> decltype( wrapper.end() )
{
return wrapper.end();
}
int main()
{
std::vector< int > coll { 2, 3, 5, 7, 11, 13, 17, 19, 23 };
for( auto x : makeFromNth( coll, 1 ) )
{
std::cout << x << '\n';
}
return 0;
}
Note that my fromNth "begin" is undefined behaviour if the size of the input is less than the offset. (If it's equal then it's well defined and begin == end). Therefore do a size check first.
Note: if you are using a recent enough version of boost then iterator_range may already provide you such a "collection" that is similar to my "FromNth".
for( auto const& s : boost::make_iterator_range( v.begin() + 1, v.end() ) )
{
process( s );
}
Note: the code above worked on CodingGround using C++11 GNU 4.8.3. (That site is very slow though). From C++14 you will not need the ->decltype statements (which are needed in C++11 for templates).
Output:
sh-4.3$ g++ -std=c++11 -o main *.cpp
sh-4.3$ main
3
5
7
11
13
17
19
23