Summary:
`std::optional` supports comparing with `std::nullopt`, so
`folly::Optional` should do the same with `folly::none`.
This also involves marking hasValue() noexcept to be the same as `std::optional`.

Reviewed By: yfeldblum, WillerZ

Differential Revision: D5617825

fbshipit-source-id: a4b863dd61c3a86223fb21a5b7759e7c295fd272

Summary:
The added API will be used for storing and retrieving validation result of client cert.

At some point we may change "client" to "peer" to make it generic.

Reviewed By: anirudhvr

Differential Revision: D5610404

fbshipit-source-id: 2feb03abc0594af4c68db33d8885ea214867148a

Summary:
Containers should not tag their default constructor explicit,
because it means that you can't return an empty one with "return {};".
This diff removes the explicit tag from small_vector's default
constructor.

Reviewed By: meyering

Differential Revision: D5602749

fbshipit-source-id: 2a4a356134c69d01e3b040719dc6ffca0fe97e75

Summary: this fixes the case where bulk inserting a range where the smallest element is equal to the largest element of the current set/map fails to deduplicate that element.

Reviewed By: mlogan, yfeldblum

Differential Revision: D5593284

fbshipit-source-id: 487500ee7a5e33f27c24321ad4a3c07a669fc26c

Summary:
[Folly] Explicitly handle gcc in `FOLLY_MAYBE_UNUSED`.

Fixes build break from {D5562220}.

Reviewed By: Orvid

Differential Revision: D5594288

fbshipit-source-id: 5aa2dcb6133d53a0eb20d34b67c8e4407dd2b7ca

Summary: [Folly] Cut unnecessary parens in `IPAddress.h`.

Reviewed By: meyering

Differential Revision: D5589756

fbshipit-source-id: 6499e0db2aeb232356e2808fc59a35869b5dad0a

Summary: [Folly] Let `IPAddressV4::bitCount` and `IPAddressV6::bitCount` be `constexpr`.

Reviewed By: meyering

Differential Revision: D5589954

fbshipit-source-id: f4208efd62e71f47a7c87bdc8ddd421f93413c29

Summary: [Folly] Apply `clang-format` to `folly/**/*Address*.*`.

Reviewed By: Orvid

Differential Revision: D5581523

fbshipit-source-id: 97b5270e43e279e7deb9606524d5fee844a50649

Summary:
Use it like this:
```
using namespace folly::string_piece_literals;
StringPiece p = "A literal string"_sp;
```

In some compilation environments it can be more efficient than the implicit
conversion from `char const *` to `StringPiece`.

Reviewed By: yfeldblum

Differential Revision: D5562782

fbshipit-source-id: ce715edc65b1510761e127bf89a6936370253a68

Summary: `Future::onError` does not work with a function that takes `exception_wrapper&`, so it should not compile. `exception_wrapper`, `const exception_wrapper&`, and `exception_wrapper&&` are unaffected.

Reviewed By: yfeldblum

Differential Revision: D5556083

fbshipit-source-id: 45d096d9fee00322eeec6b9b9b1dcbef55cced03

Summary:
[Folly] Consistent use of `sformat` in address-related files.

V.s. `format(/*...*/).str()` and v.s. `to<std::string>`.

Reviewed By: meyering

Differential Revision: D5570334

fbshipit-source-id: 83aedf9a694721fb209e62e94f1a5c5ecd355e81

Summary: [Folly] Apply `clang-format` to `folly/**/*Range*.*`.

Reviewed By: meyering

Differential Revision: D5570553

fbshipit-source-id: 230aa8557c2d402d741aaa541f96f4634dd13d3b

Summary: Make sure server can get client cert using AsyncSSLSocket::getPeerCert() call.

Reviewed By: anirudhvr

Differential Revision: D5557303

fbshipit-source-id: d95696f592e3b3f67acba9f92add32b91c29a000

Summary: ... as titled.

Reviewed By: yfeldblum

Differential Revision: D5558742

fbshipit-source-id: b63b121cde8db93de4cabc80563539297611d600

Summary:
Clang compiler does not define `__CLANG__` macro and
only defines `__clang__`, but we use `__CLANG__` in a
few places in the code which was probably done by mistake.
This should make the code behave in the intended way.

Reviewed By: yfeldblum

Differential Revision: D5542162

fbshipit-source-id: 74d24ba9464d8faec160d73e6c582967d3c80c19

Summary: Adds unique pointer type for X509_EXTENSION

Reviewed By: knekritz

Differential Revision: D5556504

fbshipit-source-id: b84190f20dd0a2ee9f5f07f197caf53a9a063af7

Summary: Remove a bunch of identical code that only exists to provide interfaces for both `const MessageT&` and `MessageT&&` arguments.

Reviewed By: ot

Differential Revision: D5540560

fbshipit-source-id: ae7b9345b64130fc748033be2e0587c4f83345a7

Summary: Speaking of errors...

Reviewed By: philippv

Differential Revision: D5545916

fbshipit-source-id: cc8471c2f0fc3cefaa9f8493d9b976098f896176

Summary: Closes https://github.com/facebook/folly/pull/649

Reviewed By: Orvid

Differential Revision: D5535534

Pulled By: yfeldblum

fbshipit-source-id: 641186d6171479755bd9471a484b8b3c2ab62418

Summary: What it says on tin

Reviewed By: knekritz

Differential Revision: D5533819

fbshipit-source-id: e3ba89f02d20d171fbcb8ed2853267d37bd86756

Summary:
[Folly] Cut debugging code from `SocketAddress`.

Specifically from its `ExternalUnixAddr` helper class, which is probably not broken.

Reviewed By: simpkins

Differential Revision: D5530685

fbshipit-source-id: adfc46ec1c1a142e9914051e8a97b39f41d71630

Summary: Also add tests for the `is_replaceable` trait.

Reviewed By: yfeldblum

Differential Revision: D5526317

fbshipit-source-id: 92559d55fbb8d115856ef9e8f86b42e327f74e56

Summary: Add an SSL Version that specifies only TLS 1.2 and up.  This prevents any client with less than TLS 1.2 from connecting.

Reviewed By: knekritz

Differential Revision: D5537423

fbshipit-source-id: 131f5b124af379eaa2b443052be9b43290c41820

Summary: Change AsyncUDPSocket's ReadCallback to be protected so that subclasses can have access to it.

Reviewed By: yangchi

Differential Revision: D5376012

fbshipit-source-id: 7ec21d9bfe6bde525253adea7abf5dea15fb7fa0

Summary:
[Folly] DRY some methods in `IPAddress`.

Specifically, the ones which just delegate to either `asV4()` or to `asV6()`.

Reviewed By: mzlee

Differential Revision: D5529797

fbshipit-source-id: 4dd3dc893ab19281325700b85400c1c1aadfd77f

Summary: Add a protected virtual sendmsg method to AsyncUDPSocket. And make it default to call the system sendmsg function. This enables subclasses of AsyncUDPSocket to be able to override the behavior of sendmseg, also makes AsyncUDPSocket easier to mock and test.

Reviewed By: afrind

Differential Revision: D5459745

fbshipit-source-id: b0227bf7503b1096cb1f0bfc8b9c784db2f2e45d

Summary:
[Folly] No need for `strncpy` in `passwordCallback`.

Careful reading of the documentation:

> The pem_passwd_cb must write the password into the provided buffer `buf` which is of size `size`.
>
> https://wiki.openssl.org/index.php?title=Manual:SSL_CTX_set_default_passwd_cb(3)&oldid=761

No mention is made of a requirement on the password being written into `buf` that it be null-terminated.

Reviewed By: knekritz, meyering

Differential Revision: D5524814

fbshipit-source-id: 6cfc588cdf3675281ffe39e6af376f3f0631d1b0

Summary: Not supported by some environments.

Reviewed By: yfeldblum

Differential Revision: D5526180

fbshipit-source-id: 2c2b6f7627860c5f896532b90601c817530e6b69

Summary: [Folly] Consistency in namespace-closing comments.

Reviewed By: Orvid

Differential Revision: D5524744

fbshipit-source-id: ced4dd2398ed6baa3ad5b68b74eee6a5d6b2b103

Summary: [Folly] Formatting for template parameters.

Reviewed By: Orvid

Differential Revision: D5525123

fbshipit-source-id: 4feb772300cfdd6ae3168fe9f59f5a951fb85d0e

Summary:
[Folly] Simplify the `StateSize` helper in `Random`.

* Using member type aliases rather than class constants means we can remove definitions.
* Partially specializing over all RNG types with `state_size` class constants means we can remove the `mersenne_twister` specializations, which have many template parameters and are a pain.

Reviewed By: Orvid

Differential Revision: D5525144

fbshipit-source-id: bc27f112ed0d9b55befe9dabe08c4d345a402435

Summary: [Folly] Outline `throw` statements in `format`.

Reviewed By: Orvid

Differential Revision: D5523933

fbshipit-source-id: 371c9ecc707e48dcc05fa4aab4fd326111466161

Summary:
[Folly] Let `MacAddress` use a helper hex-table.

The table is in the `folly::detail` namespace so it is non-public to users of folly, but the rules may not be quite as strict in at least some cases within folly.

Also the helper `unhex` function that this replaces is not `clang-format`-clean, so this lets us sidestep that.

Reviewed By: Orvid

Differential Revision: D5524229

fbshipit-source-id: 21d6938e20cd675e65499a5b64d2af934f980222

Summary: [Folly] Consistent indentation for class visibility labels (`public:`, `protected:`, `private:`). Style is +1 column relative to the `class` keyword.

Reviewed By: andrewjcg

Differential Revision: D5524869

fbshipit-source-id: 53e4b6cbda10d5b63bafbd535794a8b7ae01a8e0

Summary:
[Folly] `template<` -> `template <`.

And then apply `clang-format` style to affected `template <...>` lines.

Reviewed By: andrewjcg

Differential Revision: D5524792

fbshipit-source-id: 6614eecf384bf3e3ccc2f0cc7c5334a0cb9c76af

Summary:
[Folly] Mark two implicit ctors as `explicit`.

They did not need to be implicit.

Reviewed By: andrewjcg

Differential Revision: D5524798

fbshipit-source-id: a50bc6bfc9da2642891faf0aa38a19f46e75b9da

Summary: [Folly] Define `IPAddressV6` comparison ops in terms of its fields using `std::tie`.

Reviewed By: andrewjcg

Differential Revision: D5524248

fbshipit-source-id: 5f5f2acd6e9cfd6dfd148cc7d95bda720bf81ee9

Summary:
[Folly] Merge `IPAddressTest.h` into the `IPAddressTest.cpp`.

There is no real need to split anything out into a header file.

Reviewed By: andrewjcg

Differential Revision: D5524267

fbshipit-source-id: e128c69c7da38663f19d0ccd73edaae36c3f469a

Summary: [Folly] Outline `throw` statements in `folly/futures/`.

Reviewed By: ericniebler

Differential Revision: D5522791

fbshipit-source-id: 545185bc580ea8628075b9ecae46c2f19308e937

Summary: [Folly] Compute masks in `IPAddressV4`. Just like in `IPAddressV6`.

Reviewed By: WillerZ

Differential Revision: D5524197

fbshipit-source-id: ebeeab28304bff4f6150cf76216d170908e62aa4