This patch hardens the "test iterators" we use to test algorithms by
ensuring that they don't get double-moved. As a result of this
hardening, the tests started reporting multiple failures where we would
double-move iterators, which are being fixed in this patch.
In particular:
- Fixed a double-move in pstl.partition
- Add coverage for begin()/end() in subrange tests
- Fix tests for ranges::ends_with and ranges::contains, which were
incorrectly calling begin() twice on the same subrange containing
non-copyable input iterators.
Fixes#100709
* Guard `std::__make_from_tuple_impl` tests with `#ifdef _LIBCPP_VERSION` and `LIBCPP_STATIC_ASSERT`.
* Change `_LIBCPP_CONSTEXPR_SINCE_CXX20` to `TEST_CONSTEXPR_CXX20`.
+ Other functions in `variant.swap/swap.pass.cpp` were already using the proper test macro.
* Mark `what` as `[[maybe_unused]]` when used by `TEST_LIBCPP_REQUIRE`.
+ This updates one occurrence in `libcxx/test/libcxx` for consistency.
* Windows `_putenv_s()` takes 2 arguments, not 3.
+ See MSVC documentation: https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/putenv-s-wputenv-s?view=msvc-170
+ POSIX `setenv()` takes `int overwrite`, but Windows `_putenv_s()` always overwrites.
* Avoid non-Standard zero-length arrays.
+ Followup to #74183 and #79792.
* Add `operator++()` to `unsized_it`.
+ The Standard requires this due to [N4981][] [move.iter.requirements]/1 "The template parameter `Iterator` shall
either meet the *Cpp17InputIterator* requirements ([input.iterators])
or model `input_iterator` ([iterator.concept.input])."
+ MSVC's STL requires this because it has a strengthened exception
specification in `move_iterator` that inspects the underlying iterator's
increment operator.
* `uniform_int_distribution` forbids `int8_t`/`uint8_t`.
+ See [N4981][] [rand.req.genl]/1.5. MSVC's STL enforces this.
+ Note that when changing the distribution's `IntType`, we need to be
careful to preserve the original value range of `[0, max_input]`.
* fstreams are constructible from `const fs::path::value_type*` on wide systems.
+ See [ifstream.cons], [ofstream.cons], [fstream.cons].
* In `msvc_stdlib_force_include.h`, map `_HAS_CXX23` to `TEST_STD_VER` 23 instead of 99.
+ On 2023-05-23, 71400505ca
started recognizing 23 as a distinct value.
* Fix test name typo: `destory_elements.pass.cpp` => `destroy_elements.pass.cpp`
[N4981]: https://wg21.link/N4981
Both `std::distance` or `ranges::distance` are inefficient for
non-sized ranges. Also, calculating the range using `int` type is
seriously problematic.
This patch avoids using `distance` and calculation of the length of
non-sized ranges.
Fixes#86833.
* Fix MSVC error C2466: cannot allocate an array of constant size 0
+ MSVC rejects this non-Standard extension. Previous fixes: #74183
* Fix MSVC warning C4805: `'=='`: unsafe mix of type `'int'` and type
`'const bool'` in operation
+ AFAICT, these lambdas were copy-pasted, and didn't intend to take and
return `int` here. This part of the test is using `vector<bool>` for
random-access but non-contiguous iterators, and it's checking how many
times the projection is invoked, but the projection doesn't need to do
anything squirrely, it should otherwise be an identity.
* Fix typos: "continuous" => "contiguous".
