title: No conflicts with the variable decleare inside the main and the one decleare inside the namspace
body: <p>I'm studying c++ namespace and i made a simple code to understand it. In particular i made this code and i don't understand why it doesn't give me the compiler error that i'have already decleare the variable 'a'. Is the compiler help me in some way?</p>
  
  <pre><code>#include&lt;iostream&gt;
  using namespace std;
  namespace funzioni_e_altro
  {
      int a=5;
      int b=20;
      int c=10;
  }
  int main()
  {
      using namespace funzioni_e_altro;
      int a=0;
      cout&lt;&lt;funzioni_e_altro::a&lt;&lt;"\n";
      cout&lt;&lt;b&lt;&lt;"\n";
      cout&lt;&lt;a&lt;&lt;"\n";
   return 0;
  }
  </code></pre>
  
  <p>I expect it gave me a compiler error, but it gave me the outputs: <br/>
  5 <br/>
  20 <br/>
  0 <br/></p>