>> deduction_guide_p doesn't look like a significant expense to me; I wouldn't >> bother trying to optimize it without profile data as evidence. > >Yep, can confirm that it's insignificant. And DECL_FRIEND_CONTEXT isn't >used in any particularly hot code so the implied memory barrier of the >deduction_guide_p call doesn't matter either (though I guess it'd be good >to mark it and other such predicates 'pure' anyway).
hear, hear &
