On 20/09/2021 21.51, Uecker, Martin wrote:
> But if we adopt this syntax for contracts, shouldn't
> we add generic syntax such as:
>
> [[attribute-token : conditional-expression]]
>
> instead of having only "pre", "post", and "assert"?
> Then future extensions would benefit from syntax
> (and type?) checking even with older compilers.

I'm not good enough looking into the future to anticipate
whether all future extensions in that area will necessarily
have a condition-expression after the introducer.

I do notice that the current proposal on the table for C++

http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2388r2.html

uses "[[post r: r >= 0]]" to designate the return value as "r".
That would be incompatible with your proposed generic grammar.

Jens