Add a feature to container_internal::Layout that lets you specify some array sizes at compile-time as template parameters. This can make offset and size calculations faster.

In particular, it seems to always improve the performance of AllocSize(), and it sometimes improves the performance of other functions, e.g. when the Layout object outlives the function that created it.

PiperOrigin-RevId: 616817169
Change-Id: Id1d318d7d2af68783f9f59090d89c642be6ae558

The workaround was added for a bug in GCC < 6.1., which had since been fixed. Abseil only [supports](https://github.com/google/oss-policies-info/blob/9a9bfe8a4a12be20757497074fc2f0ecb77438ad/foundational-cxx-support-matrix.md) GCC > 7.3.1.

However, removing the workaround still trips even more recent GCC, such as 13.1. When `SizeSeq` is empty, `p` is not actually used.
Marking it as `ABSL_ATTRIBUTE_UNUSED` silences the GCC warning for that case too.

We could disable `Slices` altogether when `SizeSeq` is empty, but that would be a breaking change (even though this API is internal), and possibly hurt generic programming use (they'd have to check if their parameter packs are empty).

PiperOrigin-RevId: 616245873
Change-Id: I77f7b0b921dfd63fb01c5223851ad1d8a7da233b

`layout`: Use auto return type for functions that explicitly instantiate std::tuple in return statements

This improves readability by avoiding spelling the same type twice, the first time with even more boilerplate (e.g. `typename`).
Return type deduction is a C++14 feature, and Abseil [currently supports](https://github.com/google/oss-policies-info/blob/9a9bfe8a4a12be20757497074fc2f0ecb77438ad/foundational-cxx-support-matrix.md) C++ >= 14.

PiperOrigin-RevId: 616218396
Change-Id: I82aeec878dd69001d2cf822db6512f5a62baec02

PiperOrigin-RevId: 616083064
Change-Id: I3d69303d32431227c197247682f8dcb70f9a239d

No longer include vlog_is_on.h from log.h.  This is a breaking change.
To use VLOG_IS_ON(), absl/log/vlog_is_on.h must be included, not log.h.

PiperOrigin-RevId: 616045708
Change-Id: I59261eb5c28846557b43b040e187ec3ef36e4132

This change mainly affects 32-bit platforms. Similar to
4618865c, check for size_t overflow
in all places where string result sizes are precomputed before allocation.

PiperOrigin-RevId: 615792028
Change-Id: I71c774c5ef2c2978bd812c70e9bab36d266b7c90

This will allow us to give visibility to other Google-internal libraries. The
change is necessary since //visibility:private cannot be combined with other
specifications.

PiperOrigin-RevId: 615779561
Change-Id: I82b1edfa4e1ca280e429cf2a5e4003a1cc316a60

Imported from GitHub PR https://github.com/abseil/abseil-cpp/pull/1603

Merge e324303b1f2aaee8e4418cffb838f150a2d4f4e7 into d8027081

Merging this change closes #1603

COPYBARA_INTEGRATE_REVIEW=https://github.com/abseil/abseil-cpp/pull/1603 from adgajda:master e324303b1f2aaee8e4418cffb838f150a2d4f4e7
PiperOrigin-RevId: 615522811
Change-Id: I46a388ac62ffd42ce175dbfa04e414dd498855f8

PiperOrigin-RevId: 615504707
Change-Id: Ia0e8211bd3c3d28fd0715c8f296ec50f6a700757

Roll back extern template instatiations in swisstable due to binary size increases in shared libraries.

PiperOrigin-RevId: 615497725
Change-Id: Ic29db8923ea4ea7cd0b01b396896fa9fff8c74b0

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Change-Id: I03c3c16a0e178fce8a572ce272b7e1fd806a38a7

PiperOrigin-RevId: 615380243
Change-Id: I5400b40a6bc5ac52ece5d4fa6da7df9e4ff50855

Motivation: mitigate linker input size increase from swisstable optimizations.

Note: the changes in raw_hash_set.h are fixing build errors that happened when adding the explicit instantiations. The change in unchecked_deref is because set iterators have const reference access whereas map iterators have mutable reference access and the function is never actually called for sets (it's used in raw_hash_map) so it wasn't needed before. I'm not sure why the soo_slot/soo_iterator problems didn't cause compile errors earlier.
PiperOrigin-RevId: 615174043
Change-Id: Iac5eb2332a76e9b70021156fbb2b8def47a5391d

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Change-Id: I29070c898104c55e6563eed0eef7397441bef1d7

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Change-Id: I68fcbdd943594983c67f8e07810b05d5fa9a6f2e

PiperOrigin-RevId: 615090942
Change-Id: I7cc20a0129dcfbbddedd9e6d816bb6234bff14b3

GCC did not support <filesystem> until GCC8.

Fixes #1635

PiperOrigin-RevId: 615051227
Change-Id: If7cd5802ead40805b1ff1c3bdfc10ba6d2858ef0

PiperOrigin-RevId: 615047295
Change-Id: I86e5de8543dc1ebee6d5a526846e9121b241b0fa

PiperOrigin-RevId: 615030645
Change-Id: Ia0ff3e649c6155c44d4772ce32fbcd4c5b273cc7

PiperOrigin-RevId: 615017130
Change-Id: I73277de8ece31d6a35b47dbdb205b473324b74a2

PiperOrigin-RevId: 614701769
Change-Id: I7c2143dd467e376eb4936ef894f3413bba681419

std:: equivalents

PiperOrigin-RevId: 614687225
Change-Id: I07421db08ee9c221e561f42e3bf8345fb5321401

PiperOrigin-RevId: 614670264
Change-Id: Id6b1cffa4e104a82234130977235f1eb1021968f

Addition and subtraction operators std::array::iterator are defined only for
ptrdiff_t, which is signed, instead of size_t, which is unsigned. Therefore,
adding the index variable to ar.begin() will trigger -Wsign-conversion if
std::array::iterator is not a raw pointer because the index variable will be
implicitly converted from size_t (an unsigned type) to ptrdiff_t (a signed
type). To fix this, we explicitly static_cast index to a ptrdiff_t.
PiperOrigin-RevId: 613662928
Change-Id: I5e06c2261d7b8f167fae7bb6acece076257f8579

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Change-Id: I69f095681102e5492916085ada0eed085a75765b

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Change-Id: I6e5ca195f208b8da0d21d70b5a035bfdc64f866d

PiperOrigin-RevId: 613305668
Change-Id: Ifc247f48ea476745eaaf0dd41dbdab8404a6cafb

Details:
- We use the space for control/slots pointers as the inline buffer.
- We use a max inline capacity of 1 to make the implementation much simpler and to avoid having to randomize the iteration order for inline tables.
- For iteration of inline tables, we introduce the kSooControl buffer which just has 1 full control byte followed by 1 sentinel control byte so that incrementing yields an end() iterator. We don't access kSooControl during lookups - only iteration.
PiperOrigin-RevId: 613253492
Change-Id: Id98ff11842f8bef27ac7ed88138dc03b46ce4fa6

PiperOrigin-RevId: 613141617
Change-Id: Ife68495d4a5951b734db7407fb99686cf45a5133

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Change-Id: Id75dfd1222a0bed8ec72ce21e4a97b1d09fc9eaa

PiperOrigin-RevId: 612509928
Change-Id: I90de2e6bd229bf5cf71a27e9c491bc2794e9265f

Imported from GitHub PR https://github.com/abseil/abseil-cpp/pull/1632

Prior art for the `vector::erase` optimization:
https://github.com/AmadeusITGroup/amc/blob/efcb7be/include/amc/vectorcommon.hpp#L176-L180 https://github.com/bloomberg/bde/blob/e15f05be6/groups/bsl/bslalg/bslalg_arrayprimitives.h#L3787-L3799 https://github.com/facebook/folly/blob/d24bf04/folly/FBVector.h#L1254-L1262 https://github.com/qt/qtbase/blob/fbfee2d/src/corelib/tools/qarraydataops.h#L856-L861

Merge 6ce011079ccf945ae95434ce45ea6c5e3a088af8 into 55d28d4b

Merging this change closes #1632

COPYBARA_INTEGRATE_REVIEW=https://github.com/abseil/abseil-cpp/pull/1632 from Quuxplusone:trivial-erase 6ce011079ccf945ae95434ce45ea6c5e3a088af8
PiperOrigin-RevId: 612278964
Change-Id: I327ace8a38292b4610c6be031cc334e77c76fd35

PiperOrigin-RevId: 612201313
Change-Id: Ia9e7f146f5e1ecaffcb15de694049b716db38d02

* It is stated in prose that the methods on `absl::NoDestructor` can never return a null pointer
* Now this is annotated via nullability annotations as well

PiperOrigin-RevId: 611619075
Change-Id: I078a5628430b7b221c009a5dcb849efe30409c28

PiperOrigin-RevId: 611321915
Change-Id: Ia63e3e2f66981d9e4f5b97f6df276b8195459ba2

Instead of casting an int to the enum type where the int does not have an associated enum value, cast the enum to its underlying type. This should be no functional change but make some linters happier.

PiperOrigin-RevId: 611172311
Change-Id: I9ae10f8fa2029014236f60a90ee2ab2273c66fa5

PiperOrigin-RevId: 611151721
Change-Id: Ic7b342770fb3e1aab8e54ff125f1529534eedc3c

Workaround for NVIDIA C++ compiler being unable to parse variadic expansions in range of range-based for loop

Fixes: #1629
PiperOrigin-RevId: 611131201
Change-Id: I787731e00207b544ee16055e6e0d323a5094a433

Breaks unit tests

PiperOrigin-RevId: 611077608
Change-Id: Ie024c299af75407e9798309f8cbf76abf60f9ee2

Having DLOG(FATAL) be [[noreturn]] in debug builds makes dead-code
warnings impossible to satisfy between the release and debug build.

PiperOrigin-RevId: 610851706
Change-Id: I07104d6687e2b1a8472ee3ea876d5fd74a70574e