We should prevent accidental use of const value function parameters (eg void foo(const Bar bar)) when the user meant to use a const reference instead. Although valid, there is limited value to allowing const value parameters, and the inefficiencies that result from accidental use can be significant.

from pkasting@:
"""
There is one total time I have ever run into "const T" as an arg where it turned out to be intentional and not a typo, and in that case it wasn't actually preventing an error, the coder in question was just even more zealous than me about using const everywhere.  Whereas unintentionally typoing "const T&" this way has been an error I've seen dozens and dozens of times in Chromium.

This is why I purposefully did not propose a limited check in the form of warning about move-from-const, or warning only on "const non-BT".  The pattern has such low benefit that it's less confusing and no more harmful to entirely ban it than to try to limit the check to cases where it's going to trigger real bugs.
"""

One question is whether to limit this to non-primitive types or do it for everything.

I'm going to do a bit more investigations to see how many instances in Chromium this check would affect.