34. Safer casting with static_cast

• Use static_cast in place of most C-style casts.

• Use static_cast when converting from one type to another, and the types are related:

  • Converting to and from void*

  • Converting float to int

  • Converting enum to int

  • Other similar conversions when types are related (ptr to ptr).

  
      // Trust the programmer, with compiler help:
      double d = 3.5;
      int x = static_cast< int >( d ); // NO ROUNDING: x gets 3, not 4!
      int* p = static_cast< int* >( malloc( sizeof( int ) * 100 ) );
  
  

• Compiler will help the conversion (it may do some checking.)

• Warning: using static_cast often is not portable, because types could have different sizes on different systems.