Imported from GitHub PR https://github.com/abseil/abseil-cpp/pull/1672

https://github.com/abseil/abseil-cpp/discussions/1671

Merge ddcbb2466b2c9c4048d60be7e58cf47f935c257d into eba8db7b

Merging this change closes #1672

COPYBARA_INTEGRATE_REVIEW=https://github.com/abseil/abseil-cpp/pull/1672 from MBkkt:optimize-str-join ddcbb2466b2c9c4048d60be7e58cf47f935c257d
PiperOrigin-RevId: 633988391
Change-Id: I2b3904211a29de3a768fb90a7fc106d7ff6c03e7

PiperOrigin-RevId: 633974603
Change-Id: I7efd0f0fadf1803aa8eacb86a18366e9a8a07df0

PiperOrigin-RevId: 633738511
Change-Id: I3f895d5de1aec5b5b9666523a328f3a3b0344e59

The tests work either way, but this way the inputs are more realistic.

PiperOrigin-RevId: 633606944
Change-Id: I6c0440f2fceb5b8d9d4aed5818c3171d3fce2fb8

Both libstdc++ and libc++abi currently ship a __cxa_demangle on MIPS;
there’s no reason to avoid using it.

PiperOrigin-RevId: 633319823
Change-Id: I8d28a87f9998a62a25e0e149138395f8994e6fb5

This allows users to pass a collection of string-like objects in an
`initializer_list` without having to convert everything to the same
type first.

`initializer_list` has the requirement that everything is copied in to
the list. For strings hitting the `string_view` overload avoids
unnecessary copies.

This may be a breaking change if `absl::StrJoin` has an explicit
template parameter, for example `absl::StrJoin<std::string>({foo,
"bar"});`. In this case, remove the explicit template parameter.

PiperOrigin-RevId: 633295575
Change-Id: Ie5f0860f409f639a27a58949842ec961e0b3bdeb

PiperOrigin-RevId: 633229582
Change-Id: Ibda908d261b52b1af766304992edd77a5bdd56b5

The `if (actual != expected)` makes the `ASSERT_EQ(actual, expected)` trigger only when the assertion fails. However, a successful `ASSERT_EQ` takes a negligible amount of time, which means the `if` is useless and only makes the test harder to read.

PiperOrigin-RevId: 632487285
Change-Id: I1f78136cf4895295c88a5ff3e0bcdce6b08c1d0b

- remove [<initializer_list>](https://en.cppreference.com/w/cpp/header/initializer_list) from internal header. It declares `std::initializer_list`, `std::begin` and `std::end`, none of which are used there
- add `absl/base/attributes.h` to the internal header because it provides `ABSL_FALLTHROUGH_INTENDED`
- add [<functional>](https://en.cppreference.com/w/cpp/header/functional) to the public header, because it provides `std::reference_wrapper`

PiperOrigin-RevId: 632018125
Change-Id: Icf7a9c8a920c9c076ef416ea80995e3a81ce3e81

overload_test needs some extra dependencies to build when absl::variant
is not an alias for std::variant; these dependencies are listed in
absl/functional/BUILD.bazel but not in absl/functional/CMakeLists.txt.
Copy dependencies from BUILD.bazel to CMakeLists.txt.

PiperOrigin-RevId: 631845552
Change-Id: I63f53323b28aff36530be645b312e94b24475f53

`any_invocable`: Add public documentation for undefined behavior when invoking an empty AnyInvocable

This is currently documented in `internal/any_invocable.h`, but not in the public API.
For example, `std::function` [documents](https://en.cppreference.com/w/cpp/utility/functional/function) the fact that invoking an empty instance throws `std::bad_function_call`.

PiperOrigin-RevId: 631621604
Change-Id: I6b886a805ffa0e7aaef5f6971e1eafd14f94050c

The comment calls if `any_invocable`, but the standard ultimately chose [`move_only_function`](https://en.cppreference.com/w/cpp/utility/functional/move_only_function/move_only_function).
And `absl::AnyInvocable` does not officially track the standard.

PiperOrigin-RevId: 631612663
Change-Id: I3f21f33cd6e2c6ce06ac92a8d2a68db6f942ea1b

Imported from GitHub PR https://github.com/abseil/abseil-cpp/pull/1662

Merge 4b2c6c909b573d31a1cccba7cb72d4d8badeef8b into cba31a95

Merging this change closes #1662

COPYBARA_INTEGRATE_REVIEW=https://github.com/abseil/abseil-cpp/pull/1662 from pps83:crc-add 4b2c6c909b573d31a1cccba7cb72d4d8badeef8b
PiperOrigin-RevId: 631470883
Change-Id: I4a72be643ed341ddf0e0007418ab4a613a03db4b

PiperOrigin-RevId: 631211391
Change-Id: I68bb19d5702626ac497b05d851936aec42cc99d4

This change is a step towards simplifying `TestWithMultipleFormatsHelper` to the point where we'll be
able to handle special cases (e.g. apple's handling of nan) by changing which inputs are fed into the helper, instead of skipping them within the helper and not testing them at all.

Extracting the loop also improves readability by reducing indentation.

PiperOrigin-RevId: 631038465
Change-Id: I8b2458539d9d276093d8e7b5f373efba6a33800c

PiperOrigin-RevId: 631018414
Change-Id: Ice8efa0af4cb1f72b5d62fbbea4cb12cbead8634

CountTrailingZeroesNonzero16 and CountLeadingZeroes16 when they are
available.

GCC 14 and Clang 19 adds these new builtins. The g-suffix is for
"generic". The s-suffix on __builtin_ctzs and __builtin_clzs is for
"short". GCC never implemented the short versions and #1664 reports
GCC 14 (pre-release) gives an error here, although this may be a
pre-release bug.

Fixes #1664

PiperOrigin-RevId: 630408249
Change-Id: I4aedcc82b85430f50d025f8eb1cab089c6fcd1bc

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Change-Id: Icfe4bea2657d319cdd10902ee79af895c43602f1

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Change-Id: I14e29fe846701c1381adb4642e55843b482254c6

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Change-Id: Ibbb166cc3c0479617c8e48abe8134b59a67a578f

PiperOrigin-RevId: 630047753
Change-Id: I6ad73216bbe4e279553b9a57bd2727310091c754

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Change-Id: I24762df161f8a0ea41e59765ec68273f8607166b

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Change-Id: Ia4d15decff040add1b161cd9b472f19f562c49f9

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Change-Id: I6b9763f2a87a9259963f00815c6953927f8add73

PiperOrigin-RevId: 628091370
Change-Id: I2dd20b7f33ab99e78d63688832ab475a513aa3fd

Generic user code sometimes wants to provide more flexibility for its
own users and provide type arguments that are used as Hash/Eq in
underlying containers.

However, there is no sensible publicly available default value for it
yet.

This CL fixes this issue and provides publicly visible aliases that such
user code can use.

PiperOrigin-RevId: 627844757
Change-Id: I4c393007244ad8d998da02883c623eae1715c0df

PiperOrigin-RevId: 627807723
Change-Id: I106cfe4d3d614b26422f632e856397b8bdcf743e

to test the after-exit behavior

PiperOrigin-RevId: 627804039
Change-Id: Idc1c5fc14cea466dcc98f0d8746c02cafe887502

It is unused.
We already use code within the `TestWithMultipleFormatsHelper` to skip output verification for Apple and MSVC.

PiperOrigin-RevId: 627783586
Change-Id: Ib51374e8571aa5f4b5f1e836815188bd9bdc1536

There's no need to go through an extra layer of indirection to get this.

PiperOrigin-RevId: 627567108
Change-Id: I241851c5294417aae069047e35961ed58475e59e

Imported from GitHub PR https://github.com/abseil/abseil-cpp/pull/1653

CRC32_u64 returns uint32_t, no need to cast returned result to uint32_t

Merge 90e7b063f39c6b1559a21832d764e500e1cdd40c into 9a61b00d

Merging this change closes #1653

COPYBARA_INTEGRATE_REVIEW=https://github.com/abseil/abseil-cpp/pull/1653 from pps83:CRC32_u64-cast 90e7b063f39c6b1559a21832d764e500e1cdd40c
PiperOrigin-RevId: 626462347
Change-Id: I748a2da5fcc66eb6aa07aaf0fbc7eca927fcbb16

Imported from GitHub PR https://github.com/abseil/abseil-cpp/pull/1652

this change fixes errors emitted by MS compiler:
```
1>C:\abseil-cpp\absl\numeric\int128.h(278,20): error C4996: 'std::float_denorm_style': warning STL4042: std::float_denorm_style, std::numeric_limits::has_denorm, and std::numeric_limits::has_denorm_loss are deprecated in C++23. You can define _SILENCE_CXX23_DENORM_DEPRECATION_WARNING or _SILENCE_ALL_CXX23_DEPRECATION_WARNINGS to suppress this warning.
```

Merge 7be96350012559b2b3f3b705cb06088e0a6aaf0d into 7efc308b

Merging this change closes #1652

COPYBARA_INTEGRATE_REVIEW=https://github.com/abseil/abseil-cpp/pull/1652 from pps83:float_denorm_style-warn 7be96350012559b2b3f3b705cb06088e0a6aaf0d
PiperOrigin-RevId: 626124710
Change-Id: I5fc2b5758dcb3956164dbec1e8559f241a0d7bf7

PiperOrigin-RevId: 626124196
Change-Id: I81a9e4c35d6456ab8cd3942f9c2452c70db90678

Imported from GitHub PR https://github.com/abseil/abseil-cpp/pull/1651

Merge 6c02d45f193cb9d8e26f2f8e4db57cea384cefb2 into 9a61b00d

Merging this change closes #1651

COPYBARA_INTEGRATE_REVIEW=https://github.com/abseil/abseil-cpp/pull/1651 from pps83:ms-pragma-warn 6c02d45f193cb9d8e26f2f8e4db57cea384cefb2
PiperOrigin-RevId: 626108518
Change-Id: Idb00aca9bafbca92b231bdff7ef8c220948f134c

PiperOrigin-RevId: 626080616
Change-Id: If434be2371c1e28f9fd0133f411596bdc38bd222

* Specifically, using `absl::internal::type_identity_t` instead of a reimplementation thereof (`NoTypeDeduction`) in the `absl::InlinedVector` code

PiperOrigin-RevId: 626055714
Change-Id: I3f5a9a1c25480bc4431edbcc4784e6bc8d257f8d

PiperOrigin-RevId: 626039936
Change-Id: I6e791363bab06d66029a8565c42d158a2fe176f0

`str_format/convert_test`: Delete workaround for [glibc bug](https://sourceware.org/bugzilla/show_bug.cgi?id=22142)

RHEL7 ships an affected version of glibc, but this bug is specific to powerpc, which abseil [does not support](https://github.com/google/oss-policies-info/blob/4ec9f2a979a6c6b7bb148040347c8d2b1def09fa/foundational-cxx-support-matrix.md).

PiperOrigin-RevId: 626018125
Change-Id: I1875aee6c37e69f712ef91e41da455af9d00fb5f

Once absl's support floor moves to C++17, we'll be able to replace it with [`[[maybe_unused]]`](https://en.cppreference.com/w/cpp/language/attributes/maybe_unused).

PiperOrigin-RevId: 625680108
Change-Id: I823b70c0f833dcf9c41bca0c2566b12ec65785de

When `STRIP_LOG` is off, the internal variable `absl_log_internal_check_op_result` is passed to `absl::log_internal::LogMessageFatal()` and used in the failure message.
When `STRIP_LOG` is on, the variable is truly unused.

Applying a `ABSL_ATTRIBUTE_UNUSED` on the variable triggers `-Wused-but-marked-unused` when `STRIP_LOG` is off, not applying the attribute triggers `-Wunused-but-set-variable` when `STRIP_LOG` is on.

Define a new internal macro `ABSL_LOG_INTERNAL_ATTRIBUTE_UNUSED_IF_STRIP_LOG` that evaluates to `ABSL_ATTRIBUTE_UNUSED` when `STRIP_LOG` is on and nothing when `STRIP_LOG` is off to address both of these scenarios.

PiperOrigin-RevId: 625049155
Change-Id: Ia3f8a6ca916dd67a287bbda4b9bd6c574c92247a