19. Conversion by constructor mix-up

• Sometimes we are better off without constructor-conversions:

  
  class String {
  public:
      String( int i ) // Innocent idea: set initial size!
      {
          //...
      }
  };
  
  String foo()
  {
      return 0; // probably a typo?!
  }
  
  void bar( String const& str )
  {
      //...
  }
  
  int main( )
  {
      String s1(4);      // OK
      String s2 = 4;     // Confusing
      String s3 = foo(); // Really??
      bar(4);            // Error??
      return 0;
  }
  
  

• FYI: the above compiles just fine!

• Better solution: make constructor taking a single size argument explicit.