range based for loop with existing variable

Using a range based for loop in C++11 with an existing variable, I would expect that variable to be filled with the value of the last iteration after the loop. However, I've gotten different results when I tested it.

Example:

#include <iostream>
#include <vector>
using namespace std;

int main() {
  std::vector<int> v;
  v.push_back(2);
  v.push_back(43);
  v.push_back(99);

  int last = -50;
  for (last : v)
    std::cout << ":" << last << "\n";

  std::cout << last;
  return 0;
}

1. MSVC 2013 doesn't seem to support range based for loops without type declaration

2. GCC-5.1 either automatically introduces a new variable or sets it back to the initial value, giving

   :2
   :43
   :99
   -50

I guess MSVC is just being MSVC again, but what about GCC here? Why is last not 99 in the last line?

---

Given the definition by the standard, I would expect the behaviour I described in the first sentence.

{
  auto && __range = range_expression ; 
  for (auto __begin = begin_expr, __end = end_expr; 
       __begin != __end; ++__begin) { 
    range_declaration = *__begin; 
    loop_statement 
  } 
} 

range_declaration being last and not int last, this should modify the existing variable.