Summary:
- `HasArgumentTypes` uses nested `boost::mpl::transform` calls to strip
  reference qualifiers from the function argument types and then another
  `mpl::transform` call to remove `const` qualifiers.
- Replace the nested `mpl::transform` calls to just one call by using
  `folly::remove_cvref`.
Pull Request resolved: https://github.com/facebook/folly/pull/1086

Reviewed By: Orvid

Differential Revision: D14638843

Pulled By: yfeldblum

fbshipit-source-id: 8c360e50ffaba0328aa8e4c86245ce25d45bc01b

Reviewed By: lewissbaker

Differential Revision: D15114457

fbshipit-source-id: 0f49d631bd316fda828946971b607c94ee75250b

Summary:
- `fbstring_core` defines constants based on the host endianness.
- This is purely duplicated as these constants live in `Portability.h`.
  As such, remove them from `fbstring_core` class.
Pull Request resolved: https://github.com/facebook/folly/pull/1117

Reviewed By: Orvid

Differential Revision: D15096910

Pulled By: yfeldblum

fbshipit-source-id: ff4e828dfd1b19daeedf48bbf1719a3fd72c0843

Summary:
- Implement `erase` and `erase_if` for both `FBVector` and
  `small_vector`.
- This matches the APIs as in the C++20 Library Fundamentals v2.
Pull Request resolved: https://github.com/facebook/folly/pull/1089

Reviewed By: Orvid

Differential Revision: D15112753

Pulled By: yfeldblum

fbshipit-source-id: dc93c600fa8e7e8a7ed42d6a6e07439d4fa51204

Summary: as title

Differential Revision: D15115871

fbshipit-source-id: 16eff7f913bdd782192ffc0e06f03f1cf8f48393

Summary:
This change has no effect for normal use of the semaphore.

With try_acquire (previous change), we now allow the callers to pass their own baton.
It's possible that the caller ends up not needing to use the `post`, and simply wants to signal the semaphore. It's basically useful in scenario where the caller wants to wait for the first of multiple events.
Current code would deadlock in this scenario, this fixes it.

Reviewed By: andriigrynenko

Differential Revision: D15090395

fbshipit-source-id: 8e3d73705ef3559717b7335f6a9e9ea8bed1cb17

Summary: This provides an interface for the Semaphore, which allow async waiting for more complex usage on fiber, without the future overhead.

Reviewed By: andriigrynenko

Differential Revision: D15082111

fbshipit-source-id: 76306525509f36867999db459ee0b7c42f416b6c

Summary:
This new test should have been inside the
FOLLY_F14_VECTOR_INTRINSICS_AVAILABLE conditional compilation guard.

Reviewed By: mengz0

Differential Revision: D15114483

fbshipit-source-id: 2931be7d4abf7a4a95827052905bd219c9beff13

Summary: It's unsafe to use Future after setCallback was called (its executor may be moved out), so we have to copy its executor before that.

Reviewed By: yfeldblum

Differential Revision: D15113490

fbshipit-source-id: 2fa9c323ddfe1919b84bbfe05b6c5643d0c65703

Summary: [Folly] Let `RequestContext::setContext` and `RequestContextScopeGuard` members take `shared_ptr<RequestContex>` by reference. Saves a small amount on code size and runtime performance due to code size.

Reviewed By: spalamarchuk

Differential Revision: D15074704

fbshipit-source-id: 20f1149b8c56d6c4375d63fe21560bdda5e5ccae

Summary: [Folly] Cut unused `FutureBase::setContext_` overload taking `shared_ptr<RequestContext>`.

Reviewed By: mhorowitz

Differential Revision: D15073509

fbshipit-source-id: a8a9d37e3420168e63692ba77063452849355361

Summary: [Folly] Pass context by reference in the futures `Core`, saving on code size and a small on runtime performance due to code size.

Reviewed By: Orvid

Differential Revision: D15073282

fbshipit-source-id: 7c55b9f6a55ee7ec22fde6f3ab9da232a8ee006b

Summary: [Folly] Move the context in futures `Core::doCallback` to shrink code size and to improve runtime performance (fewer branches, fewer atomic RMWs, smaller code size).

Reviewed By: andriigrynenko

Differential Revision: D15073122

fbshipit-source-id: f1b5cb01ea9ccaa69ac5b42b01a8ee5fa1badb8a

Summary: [Folly] Cut explicit class template instantiations in futures. May save on code size when some of the given instantiations are not used, or when the given instantiations are used but when some of their members are not used.

Reviewed By: LeeHowes

Differential Revision: D15073879

fbshipit-source-id: c624d7ea1dad66f05a9958239a87737367450753

Summary:
F14NodeMap and F14ValueMap copy construction could fail to copy
the chunk overflow count in a rare case where there is a suffix of chunks
that suffers an overflow, then all of the non-overflowed keys are removed,
then the map is copied. In the copy the remaining overflowed key isn't
find()able, but it is still present on the iteration sequence. This diff
fixes the problem.

Reviewed By: WillerZ, shixiao

Differential Revision: D15105104

fbshipit-source-id: cff2073246bc301054996d4bb7e8baf9ee8c0021

Summary: As part of simplifying and removing ambiguity in the interface this removes the form of then(KeepAlive, member-function-pointer). Removing this directly removes the need to make multiple overloads, and migrating to a cleaner then(KeepAlive,...) form will delegate this to the application of the nested continuation.

Reviewed By: yfeldblum

Differential Revision: D15059814

fbshipit-source-id: 8e4481cc471b4ed2dc578c52e26f2223c2468719

Summary: Add getSecurityProtocol() to MockAsyncSocket

Reviewed By: knekritz

Differential Revision: D15099025

fbshipit-source-id: 98b1337a9016e75eff11f37899180d323b67247c

Summary: zmq4.3 bring up 4 more handshake events, add proper handling in sock monitor

Reviewed By: saifhhasan

Differential Revision: D15058676

fbshipit-source-id: d2553c7e32471a2403857741cbb77a40e50d353e

Summary:
Adds a utility that allows a coroutine to reschedule itself back onto its associated executor.

This allows coroutines to cooperatively schedule themselves.

It also allows a coroutine to force itself to be asynchronous by inserting a `co_await folly::coro::co_schedule;` as the first statement in the coroutine.

Reviewed By: andriigrynenko

Differential Revision: D15076362

fbshipit-source-id: 4a4a2978519e0709d28a3e1aa8745ee30ddc7751

Summary:
:
- Replace a call site in `DynamicParser-inl.h` using `boost::is_member_pointer`
  with the standard library equivalent.
Pull Request resolved: https://github.com/facebook/folly/pull/1085

Reviewed By: meyering

Differential Revision: D14638847

Pulled By: yfeldblum

fbshipit-source-id: 8eb95607dc7134b9bbc6974052094a92623fe776

Summary:
- Defining `FBSTRING_SANITIZE_ADDRESS` is more complicated than it needs
  to be and it is in fact not even needed now.
- Remove separate `FBSTRING_SANITIZE_ADDRESS` symbol and use
  `FOLLY_SANITIZE_ADDRESS` in places which previously used
  `FBSTRING_SANITIZE_ADDRESS`.
Pull Request resolved: https://github.com/facebook/folly/pull/1094

Reviewed By: Orvid

Differential Revision: D14969931

Pulled By: yfeldblum

fbshipit-source-id: 7c1a585180ca99d1e2f616765aa77f45c4426fb8

Summary: Migrate from Folly Format to fmt which provides smaller compile times and per-call binary code size.

Reviewed By: alandau

Differential Revision: D14954926

fbshipit-source-id: 9d2c39e74a5d11e0f90c8ad0d71b79424c56747f

Summary: Remove manual include overrides

Reviewed By: k21

Differential Revision: D15085229

fbshipit-source-id: fbd3c66184a696131c61605eeb0bba119e59af9e

Reviewed By: JunqiWang

Differential Revision: D15073399

fbshipit-source-id: 909fccfaa39da8f718b1195fa09ed2628f073c51

Remove deprecation from then that simply forwards to thenTry. Deprecation was inconsistent with defer.

Summary: Future::then that forwards directly to thenTry is to be left for compatibility with Future::defer and to keep naming simple. This removes the confusing deprecation warning.

Reviewed By: yfeldblum

Differential Revision: D15057215

fbshipit-source-id: 84103e47c958f1db602804f625591ba899e98b23

Summary: Functions were deprecated and =deleted to communicate their removal with a clear error rather than having the functions simply disappear. They have been in this state for long enough to cleanly remove them.

Reviewed By: yfeldblum

Differential Revision: D15057175

fbshipit-source-id: fc9bb193e3cc9157ef6b898f0e4b7717581c1cdd

Summary:
AFAIK, thenValue should effectively NOP if the future has an exception.
Instead, it throws. C++ throw is expensive, as the stack_unwind process
acquires a futex. If the service is seeing lots of exceptions (for example
if it's overloaded and trying to shed load) throwing results in high lock
contention.

Reviewed By: yfeldblum

Differential Revision: D13088019

fbshipit-source-id: a4bd39d8196d8691ca3a2c21a4860024b366fdac

Summary: Fix unused-argument warnings.

Reviewed By: yfeldblum

Differential Revision: D15068741

fbshipit-source-id: 486451bd9bd8575bed8a647f4531783c82c079b5

Summary:
- Since C++17, `vector::emplace_back()` returns a reference to
  the new element inserted.
- Differential Revision: D15007059 added support for these semantics in
  `small_vector`. This adds it for `FBVector` too to be symmetric.
Pull Request resolved: https://github.com/facebook/folly/pull/1114

Reviewed By: ot

Differential Revision: D15053815

Pulled By: yfeldblum

fbshipit-source-id: 73ce9687e77ee9b97f12151cc148a84613b3ed1d

Reviewed By: AhmedSoliman

Differential Revision: D15060131

fbshipit-source-id: 428f50129ec79c0f6091829dc5946163e532cde1

Summary:
* Update to zstd-1.4.x
* Update to the latest zstd-rs

Reviewed By: Cyan4973

Differential Revision: D15040909

fbshipit-source-id: 938904d95ab8b1108d750d83602ee9c11c2c87b5

Summary:
Replace Future::onError with Future::thenError:
 * to remove ambiguous typing
 * to ensure that the executor is not lost and the returned Future is still bound to an executor

This diff finally removes the legacy onError.

See:
https://fb.workplace.com/groups/fbcode/permalink/2002251863144976/
for details.

Reviewed By: yfeldblum, Orvid

Differential Revision: D15034702

fbshipit-source-id: 17faf37e79c0a31ad25c02542f09a8293e693899

Summary:
The folly::coro functionality depends heavily on the symmetric-transfer capability of coroutines which MSVC does not yet support.

The folly/Portability.h header was previously defining FOLLY_HAS_COROUTINES to true for MSVC even though you would get compile errors if you tried to use any of the folly::coro facilities.

Also further restrict defining FOLLY_HAS_COROUTINES only when C++17 or later is available as folly::coro makes use of C++17 language features.

Reviewed By: yfeldblum, andriigrynenko

Differential Revision: D14811921

fbshipit-source-id: f3da2d3c07fc9ebe08f566a7707c62e74e412df9

Summary:
Remove legacy logging API (`XLOGC` and friends) because it is not used anywhere
and is not fully safe being varargs-based. The code that needs to be converted
from `printf`-based logging can use fmt's `printf` API which is fully type-safe.

Reviewed By: simpkins

Differential Revision: D15036094

fbshipit-source-id: 3919e5d4eb7994ed0db4fa47bada111ab0dca505

Summary: temp

Reviewed By: yfeldblum

Differential Revision: D14882681

fbshipit-source-id: 3017cb9743c81396764e6a61bdca183ae2692401

Summary:
- Most of `IntToDouble` test is commented out as it previously did not
  work with GCC 4.6.1.
- Enable the rest of this test as it works fine on GCC 5.1
Pull Request resolved: https://github.com/facebook/folly/pull/1112

Reviewed By: yfeldblum

Differential Revision: D15014999

Pulled By: Orvid

fbshipit-source-id: a26a0fcacc9a22c03d0d67c35cabf8ec0ca91813

Summary: The only fix in this diff to an error currently being seen by the contbuilds is the change to concurrent hash map. The rest would have been seen when building the slow tests is enabled.

Reviewed By: yfeldblum

Differential Revision: D14898822

fbshipit-source-id: b28cd697496bb97b0e35b189a9bb31b666da3b17

Summary:
- Both GCC and Clang define the macro `__GNUC__`, `__GNUG__` and
  friends. Simplify some macros whose intent is to check "if we are GCC or
  Clang" but do so via checking `__GNUC__` in addition to `__clang__`. It
  is sufficient to just check `__GNUC__`.
Pull Request resolved: https://github.com/facebook/folly/pull/1095

Reviewed By: Orvid

Differential Revision: D14697480

Pulled By: yfeldblum

fbshipit-source-id: cd6ec82c4235a1321ecdf240afaad7d5c0e99437

Summary: [Folly] Consistent `void` return-type checks in `DistributedMutex`. `const void` is a different type from `void`, but both match the `std::is_void` predicate.

Reviewed By: aary

Differential Revision: D14638815

fbshipit-source-id: 96d1e18dfe1026b3881dafe5ceb816a8dd3add08

Summary: Since C++17 `vector::emplace_back()` returns a reference to the new element, support that in `small_vector` too.

Reviewed By: terrelln, luciang

Differential Revision: D15007059

fbshipit-source-id: 3873fd0097e3d50f7967f47fbecfa6ab20cc72c5