Examine the API of a function in a library. It says it doesn't modify anything reachable through its arguments, but is that true? How would you know? And how would you know if the API doc doesn't say?
You are right, but try to look at this from another angle (probably i am not making any sense here). Should "D const" be perceived this way?
When i say "const A", it broadly means don't assign to this.
You'd fall back to const by convention, and that is not reliable and does not scale. You have to manually go through an entire hierarchy of function calls to figure out if one might change a member of the data structure, and then after a few maintenance cycles, you have to do that all over again.
I have no idea how to solve this for documentation and such but the second you compile the source, everything will be clear as day.
