What does the C++ standard say?

[vicodin451]

I know this isn't the VC++ forum, but...
MSVC++ doesn't adhere to the standard, but the 7.x versions of the MS compiler offer a switch that you can use to force compliance in this respect. From MSDN:

The C++ standard says that a variable declared in a for loop shall go out of scope after the for loop ends. For example:

for (int i = 0 ; i < 5 ; i++) {
   // do something
}
// i is now out of scope under /Za or /Zc:forScope

By default, under /Ze, a variable declared in a for loop remains in scope until the for loop's enclosing scope ends.

/Zc:forScope enables standard behavior of variables declared in for loops without needing to specify /Za.

It is also possible to use the scoping differences of the for loop to redeclare variables under /Ze as follows:

// for_statement5.cpp
int main()
{
   int i = 0;   // hidden by var with same name declared in for loop
   for ( int i = 0 ; i < 3; i++ )
   {
   }

   for ( int i = 0 ; i < 3; i++ )
   {
   }
}

This more closely mimics the standard behavior of a variable declared in a for loop, which requires variables declared in a for loop to go out of scope after the loop is done. When a variable is declared in a for loop, the compiler internally promotes it to a local variable in the for loop's enclosing scope even if there is already a local variable with the same name.