Meaning of invariant

[Jarrett Billingsley]

"Edward Diener" <eddielee_no_spam_here at tropicsoft.com> wrote in message 
news:foldqs$47f$1 at digitalmars.com...
>I could not find any explanation for the keyword 'invariant' in the PDF 
>doc. Is it the equivalent of the C++ 'const' in at least some of the 
>latter's usages ?
>
> The only explanation for it existed as part of Contract Programming, but 
> it seems to be used otherwise also.

In D1, it's only used in Contract Programming.