What guarantees does D 'const' provide, compared to C++?

[Mehrdad]

On Friday, 17 August 2012 at 03:36:28 UTC, Chris Cain wrote:
> Combine const and pure


Yes, I 100% realize 'pure' and 'immutable' are advantages over 
C++.
The question was about 'const' by itself, though, because 
otherwise that's not a fair comparison. (The goal is comparing 
C++ const to D const, not C++ const to D const + immutable + 
purity.)