4. C++ struct initialization

• In our example we used initializer list to provide the initial values to the width and height of the rect object:

  
      Rectangle rect { 20, 10 };
  
  

• However, we may want to use other forms of the rectangle initialization:

  
      Rectangle rect; // use default values
      Rectangle rect2( 100 ); // make it a square where width = height = 100
  
  

• If we try

  
  int main()
  {
      Rectangle rect;
      std::cout << "rectangle width: " << rect.width << '\n';
      std::cout << "rectangle height: " << rect.height << '\n';
      return 0;
  }
  
  

  the output of width and height values yields undetermined result.

• An attempt to create rect2 won't even compile:

  
      Rectangle rect2( 100 ); // *** compiler error: no matching function for call