`string_view` is supported all the way back to C++03 as an extension in
`libc++`, and so many of the tests run in all standards modes for all vendors.
This is unlikely desired by other standard library vendors using our test suite.
So, disable the tests for vendors other than `libc++` in these older standards
modes.
Differential Revision: https://reviews.llvm.org/D126850
This avoids using an libc++ internal macro in our tests. This version
doesn't depend on the internal macro but redefines it.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D119460
Some embedded platforms do not wish to support the C library functionality
for handling wchar_t because they have no use for it. It makes sense for
libc++ to work properly on those platforms, so this commit adds a carve-out
of functionality for wchar_t.
Unfortunately, unlike some other carve-outs (e.g. random device), this
patch touches several parts of the library. However, despite the wide
impact of this patch, I still think it is important to support this
configuration since it makes it much simpler to port libc++ to some
embedded platforms.
Differential Revision: https://reviews.llvm.org/D111265
Implement P2251 which requires `span` and `basic_string_view` to be
trivially copyable. They already are - this just adds tests to bind that
behavior.
Reviewed By: ldionne, Quuxplusone, Mordante, #libc
Differential Revision: https://reviews.llvm.org/D111197