A span has no idea what container (if any) "owns" its iterators, nor
under what circumstances they might become invalidated.
However, continue to use `__wrap_iter<T*>` instead of raw `T*` outside
of debug mode, because we've been shipping `std::span` since Clang 7
and ldionne doesn't want to break ABI. (Namely, the mangling of functions
taking `span::iterator` as a parameter.) Permit using raw `T*` there,
but only under an ABI macro: `_LIBCPP_ABI_SPAN_POINTER_ITERATORS`.
Differential Revision: https://reviews.llvm.org/D101003
This is the initial patch to implement ranges in libc++.
Implements parts of:
- P0896R4 One Ranges Proposal
- P1870 forwarding-range is too subtle
- LWG3379 in several library names is misleading
Reviewed By: ldionne, #libc, cjdb, zoecarver, Quuxplusone
Differential Revision: https://reviews.llvm.org/D90999
I think people were sometimes parenthesizing `(foo::max)()` out of
misplaced concern that an unparenthesized `foo::max()` would trip up
Windows' `max(a,b)` macro. However, this is not the case: `max(a,b)`
should be tripped up only by an unparenthesized call to `foo::max(a,b)`,
and in fact we already do `_VSTD::max(a,b)` all over the place anyway
without any guards.
However, in order to do it without guards, we must also
wrap the header in _LIBCPP_PUSH_MACROS, which <span> was not.
Differential Revision: https://reviews.llvm.org/D92240
This change removes both the member function swap and the free function
overload of swap for std::span. While swap is a member and overloaded
for every other container in the standard library [1], it is neither a
member function nor a free function overload for std::span [2].
Thus the corresponding implementation should be removed.
[1] https://eel.is/c++draft/libraryindex#:swap
[2] https://eel.is/c++draft/span.overview
Differential Revision: https://reviews.llvm.org/D69827
This implements the relaxed requirements on the std::array constructors of span,
where the type only needs to be convertible to the element type of the span.
Note that the previous tests were not sufficient, as the const array<T, n> constructor
was only tested for compile time and the array<T, N> only during runtime.
Restructure the tests so that we can test conversions as well as both constructors.
Differential Revision: https://reviews.llvm.org/D75706
The default constructor of a static span requires _Extent == 0 so
SFINAE it out rather than using a static_assert
Differential Revision: https://reviews.llvm.org/D71994
The static asserts in span<T, N>::front() and span<T, N>::back() are
incorrect as they may be triggered from valid code due to evaluation
of a never taken branch:
span<int, 0> foo;
if (!foo.empty()) {
auto x = foo.front();
}
The problem is that the branch is always evaluated by the compiler,
creating invalid compile errors for span<T, 0>.
Thanks to Michael Schellenberger Costa for the patch.
Differential Revision: https://reviews.llvm.org/D71995
The calculation _Offset + _Count <= size() may overflow, so use
_Count <= size() - _Offset instead. Note that this is safe due to
the previous constraint that _Offset <= size().
Patch by Michael Schellenberger Costa.
Differential Revision: https://reviews.llvm.org/D71998
The extent of the returned span was always std::dynamic_extent, which
is incorrect.
Thanks to Michael Schellenberger Costa for the patch.
Differential Revision: https://reviews.llvm.org/D71997
size_t is always greater than 0, so remove the artifact from the old
index_type.
Patch by Michael Schellenberger Costa.
Differential Revision: https://reviews.llvm.org/D71996
to reflect the new license. These used slightly different spellings that
defeated my regular expressions.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351648
Summary:
Add error messages to a couple of static_asserts in span to match the
style used in the rest of the file. Also fix an extra paren typo in a
assert error message.
Committed on behalf of Jason Lovett.
Reviewers: ldionne
Subscribers: libcxx-commits
Differential Revision: https://reviews.llvm.org/D52841
llvm-svn: 343725
Christopher Di Bella