That works. We already have some things like that, like “__attribute__((always_inline))”. Of course, forcing some optimisations could implicitly prevent others,

That works. We already have some things like that, like “__attribute__((always_inline))”. Of course, forcing some optimisations could implicitly prevent others, but that’d also be true if you did it manually. With expressive enough metaprogramming, you could also do some of these explicit optimisations in user code.