Again, std::tuple may or may not rely on intrinsics today, that is not the point. We know that a growing number of library constructs do.
What are they? Concrete examples of these intrinsics, please.
A few years ago, I remember that there were laments about it being "impossible to implement std::vector with compliant code". One answer to that (the approach taken) is to supply library tools (backed by compiler intrinsics in the case of clang I believe). Another is to simply accept that vector is so useful and necessary a noun that it ought to be part of the language.
What about third-party vector-like types, such as boost::small_vector or boost::static_vector? Are they just out of luck when vector is built into the language and we don't solve how to implement it as a library? And good luck getting those containers into standard C++, because gathering field experience for things that have to be built into compilers is tough.
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