1. 26 Aug, 2019 5 commits
    • Adam Simpkins's avatar
      fbcode_builder: support installing thrift generated header files · da5c228a
      Adam Simpkins authored
      Summary:
      Update add_thrift_cpp2_library() to add a PUBLIC_HEADER property to the
      generated library target, so that the generated headers can be installed using
      an `install()` call.  Also add a `HEADER_INSTALL_DIR` property which indicates
      the directory they should be installed into.  A `INCLUDE_DIR` argument was
      added to customize the include installation path, should anyone care to do so.
      
      This also removes code that was previously incorrectly installing the
      generated headers into the source tree.
      
      Reviewed By: wez
      
      Differential Revision: D16853404
      
      fbshipit-source-id: 6f640b2bd347c99804e074fca0209dda37c8a9cf
      da5c228a
    • László Várady's avatar
      Fix sorted_vector PMR test cases (#1207) · 74f346e7
      László Várady authored
      Summary:
      `folly::detail::std_pmr` uses either `std::pmr` or `std::experimental::pmr`.
      
      "Polymorphic Memory Resources" has been standardized in C++17, but `pmr::resource_adaptor` was [left behind](https://github.com/cplusplus/papers/issues/33), which means `resource_adaptor` is not available when a C++17 ready standard library is detected by folly.
      
      This commit reimplements `test_resource` without using the non-standard adaptor.
      
      ```
      folly/test/sorted_vector_test.cpp:862:31: error: ‘folly::detail::std_pmr::resource_adaptor’ has not been declared
        862 | using folly::detail::std_pmr::resource_adaptor;
            |                               ^~~~~~~~~~~~~~~~
      ```
      Pull Request resolved: https://github.com/facebook/folly/pull/1207
      
      Reviewed By: nbronson
      
      Differential Revision: D17003049
      
      Pulled By: yfeldblum
      
      fbshipit-source-id: 7bcd5b4bb4368366cd57d89b9ef88deaaff808d6
      74f346e7
    • Tristan Rice's avatar
      folly: within - grab executor keepalive before moving · 216aaafc
      Tristan Rice authored
      Summary: Previous within changes changed how long the executor keepalive existed for. This explicitly grabs the executor keepalive before calling within to ensure it still exists when we try to use it in `via`.
      
      Reviewed By: LeeHowes
      
      Differential Revision: D17054622
      
      fbshipit-source-id: 7826c6ac0ad332a8f5f1331cd2d798619cf318c3
      216aaafc
    • Adam Simpkins's avatar
      fbcode_builder: update the old fbcode_builder spec for fbzmq · 986ce3f1
      Adam Simpkins authored
      Summary:
      The external Travis CI builds for fbzmq are still using the older
      fbcode_builder spec (as opposed to the newer getdeps manifest file).
      
      D16577367 moved the CMakeLists.txt file to the top-level directory, but the
      fbzmq spec file was still looking for it in the fbzmq subdirectory.
      
      Reviewed By: jstrizich
      
      Differential Revision: D17005361
      
      fbshipit-source-id: 3f7664eadfb60ec7606124a14445b44ae586b8a7
      986ce3f1
    • Adam Simpkins's avatar
      fbcode_builder: fix the shipit path map for fbzmq · 40e15ce0
      Adam Simpkins authored
      Summary:
      Fix the fbzmq pathmap listed in its manifest file to match the path map
      actually used by ShipIt.  The fact that this was broken was why internal
      getdeps builds did not detect that D16577367 broke the build.
      
      Reviewed By: wez, jstrizich
      
      Differential Revision: D17005360
      
      fbshipit-source-id: 046ff58ad70c03b860c3fccebaba975808df244d
      40e15ce0
  2. 25 Aug, 2019 4 commits
    • Adam Simpkins's avatar
      fbcode_builder: ThriftCppLibrary: the output depends on the thrift templates · 09ac30c9
      Adam Simpkins authored
      Summary:
      Update ThriftCppLibrary.cmake to record that the output depends on the thrift
      `cpp2` template files.  The `THRIFT_TEMPLATE_FILES` variable was defined in
      D16062657 but doesn't appear to be used anywhere.  This uses it, and also
      updates it to only match the C++ template files.
      
      Reviewed By: wez
      
      Differential Revision: D16738442
      
      fbshipit-source-id: aa4097e9ec1d009ef1e3ee2efd03ffa19a82ed12
      09ac30c9
    • Adam Simpkins's avatar
      fbcode_builder: minor style cleanup in ThriftCppLibrary.cmake · a35a5f9a
      Adam Simpkins authored
      Summary:
      Add explicit double quotes around arguments that are intended to be exactly a
      single parameter.  Also line wrap to 80 characters.
      
      Reviewed By: wez
      
      Differential Revision: D16738443
      
      fbshipit-source-id: b8c9b6d50da72b44e23eaf5effbc384b6cbbc1c0
      a35a5f9a
    • Adam Simpkins's avatar
      fbcode_builder: update ThriftCppLibrary to use fb_cmake_parse_args() · abc21143
      Adam Simpkins authored
      Summary:
      Change ThriftCppLibrary to use `fb_cmake_parse_args()`
      
      This code doesn't really care much about handling empty arguments, so we could
      use the standard `cmake_parse_arguments()` function here instead of
      `fb_cmake_parse_args()`.  However, it is slightly more convenient that
      `fb_cmake_parse_args()` automatically errors out on unhandled arguments, so
      that we don't have to check for this ourselves.
      
      Reviewed By: wez
      
      Differential Revision: D16738445
      
      fbshipit-source-id: 67b9761f2ceaf7665bd336290bb44af32fec6f4a
      abc21143
    • Adam Simpkins's avatar
      fbcode_builder: update current commit for iproute2 · 4c502a7f
      Adam Simpkins authored
      Summary:
      The manifest file for iproute2 previously listed the commit to check out as
      7ca63aef7d1b0c808da0040c6b366ef7a61f38c1.  However, this is not a commit, but
      a tag object that refers to commit 92a0236a3cdf3438000834121b7ea8a09f1f52b1.
      
      This caused getdeps to think that iproute2 was always out-of-date, even when
      it was already on the correct commit, since it was comparing current commit ID
      against the tag ID.
      
      This updates the manifest to refer to the commit ID instead of the tag ID.
      
      Reviewed By: shri-khare
      
      Differential Revision: D17005418
      
      fbshipit-source-id: c7145c73b66ae93a2e9097ddcf8c53237b135d32
      4c502a7f
  3. 24 Aug, 2019 2 commits
    • Dan Melnic's avatar
      Enable FOLLY_TLS on FOLLY_MOBILE too · 2f828c04
      Dan Melnic authored
      Summary: Enable FOLLY_TLS on FOLLY_MOBILE too
      
      Reviewed By: guangyfb
      
      Differential Revision: D16883165
      
      fbshipit-source-id: 1a8f0991088f6963dc2acf84b74b294be998b877
      2f828c04
    • Yedidya Feldblum's avatar
      Avoid __forceinline for catch_exception under MSVC · 2fc030b4
      Yedidya Feldblum authored
      Summary: [Folly] Avoid `__forceinline` for `catch_exception` under MSVC, which warns about functions which contain `try`-and-`catch` blcoks having the `__forceinline` modifier.
      
      Reviewed By: akrieger
      
      Differential Revision: D16982707
      
      fbshipit-source-id: 68c443c4ce8ca77edd49d509a88ef4b0ab9488a9
      2fc030b4
  4. 23 Aug, 2019 4 commits
    • Aaryaman Sagar's avatar
      Fix definition of SynchronizedBase::RLockedPtr · 16b42cc0
      Aaryaman Sagar authored
      Summary:
      The definition of RLockedPtr should use a non-const Subclass type, and not a
      const one.
      
      Reviewed By: ot
      
      Differential Revision: D15356827
      
      fbshipit-source-id: b8ad41e263f0e15ffa25b0698aa85eab8ca2ccb8
      16b42cc0
    • Tristan Rice's avatar
      folly: move SemiFuture::within to be with the other within methods · 7cfb9591
      Tristan Rice authored
      Summary: This moves within to be in a more logical spot. In the parent diff we kept it where it was to make it easier to see the differences.
      
      Reviewed By: LeeHowes
      
      Differential Revision: D16967106
      
      fbshipit-source-id: 9f9cd2ea38a996ac12d3ca8256c1ec050d57dfc0
      7cfb9591
    • Tristan Rice's avatar
      folly: make within be a SemiFuture and fix deadlock bug · 4594bbdf
      Tristan Rice authored
      Summary:
      This fixes a deadlock bug where the after continuation runs inline.
      
      We resolve this by using defer to delay execution until both futures are created thus avoiding any extra synchronization.
      
      Reviewed By: LeeHowes
      
      Differential Revision: D16952748
      
      fbshipit-source-id: a88a40d3135bdabc43bb51f9b5ea072f8e6564a3
      4594bbdf
    • Joe Romano's avatar
      Add docs to insert_or_assign re: inconsistency with std::map interface · 33fb91d9
      Joe Romano authored
      Summary:
      `ConcurrentHashMap::insert_or_assign` does not follow the interface for `std::map::insert_or_assign`.  Making this clear for future users to avoid confusion.
      
      Code:
      ```
      int main(int argc, char** argv) {
        folly::ConcurrentHashMap<int, std::string> map;
        std::cout << "Insertion took place?: " << map.insert_or_assign(1, "hey").second << std::endl;
        std::cout << "Insertion took place?: "
      << map.insert_or_assign(0, "wow").second << std::endl;
        std::cout << "Insertion took place?: "
      << map.insert_or_assign(1, "wow").second << std::endl;
      }
      ```
      
      Output:
      ```
      Insertion took place?: 1
      Insertion took place?: 1
      Insertion took place?: 1
      ```
      
      Also see: https://github.com/facebook/folly/blob/master/folly/concurrency/test/ConcurrentHashMapTest.cpp#L86-L87
      
      Reviewed By: magedm
      
      Differential Revision: D16967939
      
      fbshipit-source-id: ce0d32813371b31a94e14e404665d4fb2e7ffdfe
      33fb91d9
  5. 22 Aug, 2019 6 commits
    • Lewis Baker's avatar
      Add cancellable folly::coro::sleep() · 1a0ddc9c
      Lewis Baker authored
      Summary:
      Adds folly::coro::sleep() function as an alternative to using folly::futures::sleep().
      
      The coro version returns a Task<void> and supports cancellation of the sleep operation when awaited within another Task.
      
      Reviewed By: kirkshoop
      
      Differential Revision: D16816328
      
      fbshipit-source-id: 46bc4ee2475e6bd0bdfd0f7f30f3e0f1ea54d4d5
      1a0ddc9c
    • Lewis Baker's avatar
      Integrate CancellationToken support into Task · 14959740
      Lewis Baker authored
      Summary:
      The `folly::coro::Task` coroutine type now has an associated `CancellationToken` that is implicitly passed down to child operations that it awaits.
      
      This is a first step towards supporting cancellation of persistent async streams.
      
      This adds a new `co_withCancellation()` customisation point that awaitable types can customise to allow them to opt-in to cancellation. Currently only `Task` customises this operation.
      
      Also provided a new `co_current_cancellation_token` object that can be awaited within a `Task` to retrieve the current `CancellationToken`.
      
      Note that I have not yet hooked up the `Future` or `SemiFuture` to integrate with this cancellation mechanism (most `Future`-based code is not cancellation-aware). So a coroutine that is currently suspended awaiting for a `Future` may not currently respond to a cancellation request.
      
      Reviewed By: andriigrynenko
      
      Differential Revision: D16610810
      
      fbshipit-source-id: 72a31d7a3ba4c281db54c1942ab41d4ea2f34d21
      14959740
    • Giuseppe Ottaviano's avatar
      Turn MemoryMapping::LockFlags into a struct of bools · fbb2e01e
      Giuseppe Ottaviano authored
      Summary: `LockFlags` is a set of flags that mirrors `mlock2(..., int flags)`, but since this is not a C API we don't need a bitset, we can just use a more idiomatic struct of bools (also used for the other options in the class). Furthermore, having an entry with value 0 (`LOCK_PREFAULT`) does not make sense in a bitset.
      
      Reviewed By: yfeldblum
      
      Differential Revision: D16900127
      
      fbshipit-source-id: 6477854121c0626e0f36cb7a50d50df73323bd4e
      fbb2e01e
    • Wez Furlong's avatar
      watchman: only enable eden support for FB internal builds · da621b8f
      Wez Furlong authored
      Summary:
      This simplifies things for the OSS CI situation in
      the short term, especially since Eden isn't quite buildable
      or usable outside FB at this time.
      
      Reviewed By: chadaustin
      
      Differential Revision: D16953346
      
      fbshipit-source-id: 028150bb3cfc9a8ccbe1197321214b56ad359463
      da621b8f
    • Yedidya Feldblum's avatar
      Drop workaround for clang-3.6 in Range ctor · bebe69e7
      Yedidya Feldblum authored
      Summary: [Folly] Drop workaround for clang-3.6 in `Range` ctor.
      
      Reviewed By: gkmhub, Orvid
      
      Differential Revision: D16945307
      
      fbshipit-source-id: d70d7560375d0c020b19fbac227767605459a834
      bebe69e7
    • Rosen Penev's avatar
      JemallocHugePageAllocator: bzero to memset (#1195) · 24cde640
      Rosen Penev authored
      Summary:
      bzero is deprecated and can be compile time disabled for uClibc-ng
      Pull Request resolved: https://github.com/facebook/folly/pull/1195
      
      Reviewed By: Orvid
      
      Differential Revision: D16451837
      
      Pulled By: yfeldblum
      
      fbshipit-source-id: 929a8e8cd7f8ddb3a904c1b1956a5f8ca115244f
      24cde640
  6. 21 Aug, 2019 7 commits
    • Lewis Baker's avatar
      Remove iterator interface for folly::coro::AsyncGenerator · fbba622d
      Lewis Baker authored
      Summary:
      Simplified the interface for consuming an AsyncGenerator to now just have a single async next() method instead of an iterator-based API.
      
      The iterator-based API was added to integrate with the 'for co_await' syntax present in the Coroutines TS, however this syntax has been removed from C++20 to allow for future exploration of the AsyncRanges design-space.
      
      The `co_await gen.next()` expression produces an optional-like object that lets you query whether the result is a sentinel or contains a value.
      
      Old:
      ```
      Task<void> consume(AsyncGenerator<T> gen) {
        for (auto it = co_await gen.begin();
             it != gen.end();
             co_await ++it) {
          use(*it);
        }
      }
      ```
      
      New:
      ```
      Task<void> consume(AsyncGenerator<T> gen) {
        while (auto item = co_await gen.next()) {
          use(*item);
        }
      }
      ```
      
      Reviewed By: andriigrynenko, kirkshoop
      
      Differential Revision: D16586151
      
      fbshipit-source-id: 4b0bf31ba9291d894a18e9553513eddee0cde33a
      fbba622d
    • Amir Livneh's avatar
      Remove unused TestAsyncUDPSocket · 9cd581b6
      Amir Livneh authored
      Reviewed By: Orvid
      
      Differential Revision: D16640245
      
      fbshipit-source-id: 3a184e4d877ea27a9400de5993b494095f6bd5e5
      9cd581b6
    • Luca Niccolini's avatar
      do not build proxygen and mvfst for Windows (yet) · e9691bca
      Luca Niccolini authored
      Summary:
      does not affect the github build.
      this is for fb CI
      
      Reviewed By: dddmello
      
      Differential Revision: D16935982
      
      fbshipit-source-id: 61656fa600f19438b5aa89486486ed4ee103dea4
      e9691bca
    • Aaryaman Sagar's avatar
      Make folly::Hash work with pointer and pointer-like types · b3410b78
      Aaryaman Sagar authored
      Summary:
      folly::Hash did not work with pointer-like types like std::unique_ptr<T>,
      std::shared_ptr<T> and T*.  Add specializations for those
      
      Reviewed By: yfeldblum
      
      Differential Revision: D16134842
      
      fbshipit-source-id: 78d3cf9c6f5ef4f49b008c0d1c489d3c6203ba89
      b3410b78
    • Michael Lee's avatar
      Move folly/Benchmark.h from test/FBVectorTestUtil.h to test/FBVectorBenchmark · 83a5c644
      Michael Lee authored
      Summary: As far as I can tell, folly/test/FBVectorTestUtil.h does not need to include folly/Benchmark.h. Move it to folly/testFBVectorBenchmark where it is actually used.
      
      Reviewed By: yfeldblum
      
      Differential Revision: D16931137
      
      fbshipit-source-id: 8ef5f99a783537672d55883adadd08270e318a61
      83a5c644
    • Dan Melnic's avatar
      Fix : iterating through ConcurrentHashMapSIMD results in infinite loop · f3930359
      Dan Melnic authored
      Summary: Fix : iterating through ConcurrentHashMapSIMD results in infinite loop
      
      Reviewed By: nbronson
      
      Differential Revision: D16923826
      
      fbshipit-source-id: c8b98ef13034240c162c155cf0e5c3f097b73c7f
      f3930359
    • Elliott Clark's avatar
      Don't overflow/underflow in folly::stats::detail::Bucket · 8973236c
      Elliott Clark authored
      Summary: Underflow/overflow of signed integers is fraught with dangers. So this diff removes the potential for overflow while adding or subtracting buckets in folly stats.
      
      Reviewed By: yfeldblum
      
      Differential Revision: D16898755
      
      fbshipit-source-id: 4d3df1024b4c01ea0b276278105071e62e27fa27
      8973236c
  7. 20 Aug, 2019 4 commits
    • Wez Furlong's avatar
      getdeps: fixup testpilot new test recording · 1dd79077
      Wez Furlong authored
      Summary:
      In the Facebook infrastructure the testpilot runner talks
      to a service to determine whether a given test should be run locally.
      
      The remote service was returning an error for some tests because they
      didn't have enough configuration specified.
      
      This diff associates some configuration with the tests based on the
      host type and makes things happier.
      
      Reviewed By: Ben0mega
      
      Differential Revision: D16894682
      
      fbshipit-source-id: b6f59b112991160ef26cc126e98041d8908a6273
      1dd79077
    • Nathan Bronson's avatar
      add tests for sized deallocation of size zero · 2cf2b4f9
      Nathan Bronson authored
      Summary:
      Sized deallocation via ::operator delete with size == 0 is
      broken in some allocators.  This diff adds a unit test that ensures we
      are either disabling sized deallocator or running with a good allocator.
      
      Reviewed By: interwq
      
      Differential Revision: D10857654
      
      fbshipit-source-id: 981c7bcc1b021d4cd1ea1725ccf510d1958842fd
      2cf2b4f9
    • Ming Zhao's avatar
      Switch dev mode debug level from -g2 to -g1 since dev mode implies build as fast as possible. · 202eace0
      Ming Zhao authored
      Reviewed By: pixelb
      
      Differential Revision: D15301144
      
      fbshipit-source-id: f94a805427b6fc8b20e7c01fcf6e1853fbebf7f1
      202eace0
    • Victor Zverovich's avatar
      Don't fail on EINPROGRESS error in bind · 2e6e2196
      Victor Zverovich authored
      Summary: Make `AsyncServerSocket` not fail on `EINPROGRESS` in `bind` and fix handling of `errno` there.
      
      Reviewed By: yfeldblum
      
      Differential Revision: D16791566
      
      fbshipit-source-id: 1aeaefb6bae47bf41fd2d20238b716b84d0566d1
      2e6e2196
  8. 19 Aug, 2019 6 commits
    • Aaryaman Sagar's avatar
      Fix test build break · ce5afdc6
      Aaryaman Sagar authored
      Summary: T52681488
      
      Reviewed By: Orvid
      
      Differential Revision: D16901429
      
      fbshipit-source-id: 0a5fc218edf6ef29b100365163102dbdc2abf313
      ce5afdc6
    • Yedidya Feldblum's avatar
      Suppress a spurious MSVC warning in folly/Traits.h · 9bcfff7a
      Yedidya Feldblum authored
      Summary:
      [Folly] Suppress a spurious MSVC warning in `folly/Traits.h`.
      
      ```
      folly\traits.h(645): warning C4287: '>': unsigned/negative constant mismatch
      folly\traits.h(646): warning C4287: '<=': unsigned/negative constant mismatch
      folly\traits.h(647): warning C4287: '<': unsigned/negative constant mismatch
      ```
      
      Reviewed By: Orvid
      
      Differential Revision: D16889045
      
      fbshipit-source-id: 31edd58bf046143092a5f006ee0ac5b071b539a0
      9bcfff7a
    • Yedidya Feldblum's avatar
      Fix MSVC conversion warning in Optional test · 05a06785
      Yedidya Feldblum authored
      Summary:
      [Folly] Fix MSVC conversion warning in `Optional` test.
      
      ```
      folly\optional.h(372): warning C4244: 'argument': conversion from 'double' to 'int', possible loss of data
      folly\optional.h(358): note: see reference to function template instantiation 'void folly::Optional<Type>::construct<std::initializer_list<_Ty>&,double>(std::initializer_list<_Ty> &,double &&)' being compiled
                with
                [
                    _Ty=int
                ]
      folly\optional.h(359): note: see reference to function template instantiation 'void folly::Optional<Type>::construct<std::initializer_list<_Ty>&,double>(std::initializer_list<_Ty> &,double &&)' being compiled
                with
                [
                    _Ty=int
                ]
      folly\optional.h(449): note: see reference to function template instantiation 'folly::Optional<Type>::Optional<std::initializer_list<_Ty>&,double>(folly::Optional<Type>::PrivateConstructor,std::initializer_list<_Ty> &,double &&) noexcept' being compiled
                with
                [
                    _Ty=int
                ]
      folly\optional.h(451): note: see reference to function template instantiation 'folly::Optional<Type>::Optional<std::initializer_list<_Ty>&,double>(folly::Optional<Type>::PrivateConstructor,std::initializer_list<_Ty> &,double &&) noexcept' being compiled
                with
                [
                    _Ty=int
                ]
      folly\test\optionaltest.cpp(659): note: see reference to function template instantiation 'folly::Optional<Type> folly::make_optional<Type,int,double>(std::initializer_list<_Ty>,double &&)' being compiled
                with
                [
                    _Ty=int
                ]
      ```
      
      Reviewed By: Orvid
      
      Differential Revision: D16889085
      
      fbshipit-source-id: c59f5e3fa0d4402e1b836841dff66d73b111235f
      05a06785
    • Victor Zverovich's avatar
      Fix building projects that use target_compile_features · 240c1593
      Victor Zverovich authored
      Summary:
      Building a project that uses folly and `target_compile_features` may fail
      because folly requires C++14 and CMake doesn't know about it. So if a project
      has only C++11 features in `target_compile_features` CMake will pick
      `-std=gnu++11` or similar and compilation will fail on an assertion in
      `folly/Portability.h`. To fix this, add `target_compile_features` to the
      `folly` target pushing the minimum required standard to C++14.
      
      Reviewed By: Orvid
      
      Differential Revision: D16884888
      
      fbshipit-source-id: 0e5ac4abde10b1ea757011bcd05b17d508859b4f
      240c1593
    • Adam Simpkins's avatar
      fbcode_builder: CMake functions for building standalone python programs · bca45896
      Adam Simpkins authored
      Summary:
      Add some CMake functions for building standalone executables from Python
      source files.  This generates executables similar to PEX
      (https://github.com/pantsbuild/pex).
      
      In the future this could potentially be leveraged to directly build XAR files
      (https://github.com/facebookincubator/xar).
      
      The main advantages of these functions is that they allow easily defining
      "libraries" of python files, and their dependencies, which can then be used
      and packaged as part of multiple different standalone executables.
      
      Reviewed By: wez
      
      Differential Revision: D16722499
      
      fbshipit-source-id: e1d829b911dc428e5438b5cf9cebf99b3fb6ce24
      bca45896
    • Dan Melnic's avatar
      Avoid SIGSEGV if getIOExecutor() returns null · 7329a2b5
      Dan Melnic authored
      Summary: Avoid SIGSEGV if getIOExecutor() returns null
      
      Reviewed By: yfeldblum
      
      Differential Revision: D16859157
      
      fbshipit-source-id: 00c7a45677c61d84a10486f11b4f792093ac2ff5
      7329a2b5
  9. 18 Aug, 2019 2 commits
    • Orvid King's avatar
      Disable an additional warning on windows · 651dace4
      Orvid King authored
      Summary:
      It's spammy and is just informational.
      
      Created from Diffusion's 'Open in Editor' feature.
      
      Reviewed By: yfeldblum
      
      Differential Revision: D16886741
      
      fbshipit-source-id: 29aecb8a62cac9a60cbc4cabc596fd1ee00cfc04
      651dace4
    • Yedidya Feldblum's avatar
      Cut IsRelocatable of containers · cd5c885f
      Yedidya Feldblum authored
      Summary:
      [Folly] Cut IsRelocatable markings of containers, removing forward declarations of the containers to avoid over-inclusion and to avoid undefined behavior.
      
      > 16.5.4.2.1 [namespace.std]\1
      > Unless otherwise specified, the behavior of a C++ program is undefined if it adds declarations or definitions to namespace std or to a namespace within namespace std.
      
      Closes #1203.
      Closes #1204.
      
      Reviewed By: igorsugak
      
      Differential Revision: D16855473
      
      fbshipit-source-id: 0e6acc4f589707aa79b0001b415bcadfab652d62
      cd5c885f