Otherwise, this breaks freestanding builds, where `main()` isn't mangled
specially and we need to assume that we have a `int main(int, char**)`
entry point in each test for things to work.
1. for constructors that takes cvref variation of tuple<UTypes...>, there
used to be two SFINAE helper _EnableCopyFromOtherTuple,
_EnableMoveFromOtherTuple. And the implementations of these two helpers
seem to slightly differ from the spec. But now, we need 4 variations.
Instead of adding another two, this change refactored it to a single one
_EnableCtrFromUTypesTuple, which directly maps to the spec without
changing the C++11 behaviour. However, we need the helper __copy_cvref_t
to get the type of std::get<i>(cvref tuple<Utypes...>) for different
cvref, so I made __copy_cvref_t to be available in C++11.
2. for constructors that takes variations of std::pair, there used to be
four helpers _EnableExplicitCopyFromPair, _EnableImplicitCopyFromPair,
_EnableImplicitMoveFromPair, _EnableExplicitMoveFromPair. Instead of
adding another four, this change refactored into two helper
_EnableCtrFromPair and _BothImplicitlyConvertible. This also removes the
need to use _nat
3. for const member assignment operator, since the requirement is very
simple, I haven't refactored the old code but instead directly adding
the new c++23 code.
4. for const swap, I pretty much copy pasted the non-const version to make
these overloads look consistent
5. while doing these change, I found two of the old constructors wasn't
marked constexpr for C++20 but they should. fixed them and added unit
tests
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D116621
When merging the changes of <type_traits> header with the commits on
this header over the last month, several conflicts were mistaken
resolved and the wrong branch was picked while resolving conflicts,
which leads to CI failure. In order to resolve the conflicts properly
with qualification CI job, this change is reverted.
This reverts commit 95733a55b9.
1. for constructors that takes cvref variation of tuple<UTypes...>, there
used to be two SFINAE helper _EnableCopyFromOtherTuple,
_EnableMoveFromOtherTuple. And the implementations of these two helpers
seem to slightly differ from the spec. But now, we need 4 variations.
Instead of adding another two, this change refactored it to a single one
_EnableCtrFromUTypesTuple, which directly maps to the spec without
changing the C++11 behaviour. However, we need the helper __copy_cvref_t
to get the type of std::get<i>(cvref tuple<Utypes...>) for different
cvref, so I made __copy_cvref_t to be available in C++11.
2. for constructors that takes variations of std::pair, there used to be
four helpers _EnableExplicitCopyFromPair, _EnableImplicitCopyFromPair,
_EnableImplicitMoveFromPair, _EnableExplicitMoveFromPair. Instead of
adding another four, this change refactored into two helper
_EnableCtrFromPair and _BothImplicitlyConvertible. This also removes the
need to use _nat
3. for const member assignment operator, since the requirement is very
simple, I haven't refactored the old code but instead directly adding
the new c++23 code.
4. for const swap, I pretty much copy pasted the non-const version to make
these overloads look consistent
5. while doing these change, I found two of the old constructors wasn't
marked constexpr for C++20 but they should. fixed them and added unit
tests
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D116621
Hui Xie