assigned to @ldionne

A few minutes of looking through the standard did not turn up any requirement that tuple<> be trivially constructible.

trivially destructible, yes.

4 If is_trivially_destructible_v is true for all Ti, then the destructor of tuple is trivial.

constexpr, yes.

The defaulted move and copy constructor of tuple<> shall be constexpr functions.

Can you tell me where you believe this requirement comes from?

I have no idea if the standard requires this, but it would be a nice to have extension if it doesn't. Specially considering that libstdc++ has it.

I have no idea if the standard requires this, but it would be a nice to have
extension if it doesn't. Specially considering that libstdc++ has it.

Generally speaking, I'm philosophically opposed to "things that everyone does, but aren't in the standard".

If this is a good thing, then we should write it into the standard.

I think it's a reasonable thing to do as a matter of QOI. The change is very simple, too, and it's the natural way to write that default constructor IMO.

Review here: https://reviews.llvm.org/D62618

Fixed in r363075.