Undoc'd Feature?

[RPNerd]

(07-10-2022 10:22 AM)toml_12953 Wrote:  I'd think the sequence would be

1) store the current value of a (5) back in a
2) increment a

This would still give 5, though.

Actually, no, it would yield 6 (store 5 in a and then increment a), which is possibly what the M$ compiler is doing. This is wrong, IMO, because the C/C++ standard clearly states that the result of an expression consisting of a post-incremented variable is the initial value of that variable. We are therefore totally justified in expecting "a = a++;" to assign to the variable a the value of the expression "a++", i.e.: the initial value of a. The evaluation should happen before the assignment.

If a M$ compiler (and only that compiler) is returning anything else then I think we can chalk it up to some kind of compiler optimisation producing yet another "feature, not a bug".