[dchichkov]

Would you guarantee that optimizers wouldn't use heuristics at IPO stage?

Either way, you are right, and my comment should have been: 1) constraint 2) providing clues to developers 3) providing clues to optimizer.

[gsg]

Without yielding useful information, const annotations can't hope to have any positive effect on compiler optimisations, fancy or not.

I agree that const is useful for the other reasons you mention.