Why doesn't VC++ 2010 Express require stdio.h in this program but gcc++ does?

I have the following code

#include <iostream>
 
 using namespace std;
 
 void WaitForEnter()
 {
     while(1)
     {
         if('\n' == getchar()) 
         {
             break;
         }
     }
 }
 
 int main()
 {
     cout<< "Press Enter to Exit... ";
     WaitForEnter();
 }
 

This compiles on Microsoft Visual C++ 2010 Express and does what I expected. On Ubuntu using code::blocks and gcc++ 4.7 the build fails with the following error: 'getchar' was not declared in this scope. If I add the line #include "stdio.h", the program compiles and runs with the expected behavior. Why does this program compile using MVC++ 2010 Express without stdio.h but not for code::blocks with gcc++ 4.7 on Ubuntu.

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