Pull in r283944 from upstream libc++ trunk (by Eric Fiselier):
Fix std::pair on FreeBSD
Summary:
FreeBSD ships an old ABI for std::pair which requires that it have
non-trivial copy/move constructors. Currently the non-trivial
copy/move is achieved by providing explicit definitions of the
constructors. This is problematic because it means the constructors
don't SFINAE properly. In order to SFINAE copy/move constructors they
have to be explicitly defaulted and hense non-trivial.
This patch attempts to provide SFINAE'ing copy/move constructors for
std::pair while still making them non-trivial. It does this by adding
a base class with a non-trivial copy constructor and then allowing
pair's constructors to be generated by the compiler. This also allows
the constructors to be constexpr.
Reviewers: emaste, theraven, rsmith, dim
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D25389
This should fix building www/chromium 57.0.2987.110 on stable/10 and
stable/9 without having to use -D_LIBCPP_TRIVIAL_PAIR_COPY_CTOR=1 (which
changes the ABI). Direct commit to stable/10 and stable/9, since head
already has libc++ 4.0, which includes this fix.
git-svn-id: svn://svn.freebsd.org/base/stable/9@315915
ccf9f872-aa2e-dd11-9fc8-
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