Question

In this code:

for ( ;(auto i = std::find(some_string.begin(),some_string.end(),'%')) != some_string.end();)
    {

    }  

I’m getting error from gcc 4.7.1:

error: invalid use of 'auto'|   

any ideas why? shouldn’t that be correctly compiled?

Answer 1

I think it has nothing to do with auto. You just cannot declare variables in random places, for example this will not compile either – an equivalent of what you were trying to do, but without auto:

int main() {
  for ( ; (int i = 0) != 1; ++i)
    ;   
  return 0;
}