Re: Variables in for loop (style issue)

Geoff Carlton wrote:
  > Walter Bright wrote:
  >
  >>There's got to be a better way - one that offers self-documentation as
  >>well as a language guarantee that if code plays by the language rules,
  >>then const is really constant.
  >>
  >
  >
  > Good luck with your search!
  >
  > The main utility I have with const in C++ is with basic value types, and
  > one very common case is using const to avoid passing by value. That
  > is, returning "const T&" rather than "T".

Well, it not just that we want to avoid passing by value, it's also a
matter of encapsulation:

class Photon
{
    vector3 direction_;
    vector3 color_;
public:

   const vctor3& direction() const;
   ...
}

Without const we can choose between

1. bad encapsulation (we return a mutable reference)

2. bad performance (we return a copy or the value type is immutable)

Pick your poison

-Thorsten

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