Export of internal Abseil changes.

--
cd076f55c1fa600131f6dda392533dfe61679fc0 by Abseil Team <absl-team@google.com>:

Internal change

PiperOrigin-RevId: 224008762

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e05f62b01286d51044ff86ec6ef565749b9faf82 by Abseil Team <absl-team@google.com>:

Create a pow10() test helper function to compute guaranteed-precise double values of 10^x. Not all standard libraries ship bit-accurate pow() functions, causing tests to fail that rely on expected values generated by it.

PiperOrigin-RevId: 223883762

--
fd88e5e3f7ab80f7f5df9fd1488cd58b4573be69 by Abseil Team <absl-team@google.com>:

Remove some absl:: qualifications to work around inline namespace bugs on MSVC 2015.

PiperOrigin-RevId: 223869642

--
6276cfff969d596edd36a2bbaba65ee045808903 by Abseil Team <absl-team@google.com>:

Update absl/memory/CMakeLists.txt to use new functions
i.e. absl_cc_(library|test)

PiperOrigin-RevId: 223854224

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359de9afc7a34c975fd3e0cbc52afd96637d97bd by Chris Kennelly <ckennelly@google.com>:

Mark spinlock_benchmark_common as alwayslink = 1.

PiperOrigin-RevId: 223844536

--
450cd8cbe2789a6d54ed1eb87170259bb334f8b9 by Abseil Team <absl-team@google.com>:

Support .* (pointer-to-member dereference) expressions in demangle.cc.

PiperOrigin-RevId: 223826797

--
772ca92179c3634f3e31a80bbc272ed8022e3572 by Abseil Team <absl-team@google.com>:

Fix misspellings in absl::variant comments and replace a ' with a `.

PiperOrigin-RevId: 223807911

--
35dcdc2fbf299d195658aac101887f6dcad1de2f by Abseil Team <absl-team@google.com>:

Bug fix in CMakeLists.txt file (SRCS --> HDRS).

The compressed_tuple header-only library is being defined
with the SRCS parameter instead of the HDRS parameter and
this has been observed to cause some builds on some platforms
to attempt to create a static library from it which fails
since there are no .cc sources.

PiperOrigin-RevId: 223805367

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4a57a3d2045bb137c0c97958e45ce425190b8d3e by Chris Kennelly <ckennelly@google.com>:

Add test that absl::make_unique value initializes memory.

PiperOrigin-RevId: 223801819

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dfe8289d7f4dcc6bb568a26aaf192a89e896bdfd by Chris Kennelly <ckennelly@google.com>:

SpinLock: Use exchange to avoid missing wakeups.

The default fast path for SpinLock::Unlock does not use an atomic.  If the
SpinLock becomes contended while we are unlocking between lockword_.load and
lockword_.store, we will fail to wake up the new waiter.  This can cause
unexpected latency spikes.

PiperOrigin-RevId: 223800369

--
9b9d35df786482f0016f77dd31691eff81503d23 by Abseil Team <absl-team@google.com>:

Update absl/hash/CMakeLists.txt to use new functions
i.e. absl_cc_(library|test)

PiperOrigin-RevId: 223755819

--
c2014e2704b87e7cdce2d2a0287c7e2397752296 by Abseil Team <absl-team@google.com>:

Update absl/debugging/CMakeLists.txt to use new functions
i.e. absl_cc_(library|test)

PiperOrigin-RevId: 223751986

--
d83a4e09126400e3fd80645cb03ee558f532271e by Derek Mauro <dmauro@google.com>:

Cleanup synchronization benchmarks.

PiperOrigin-RevId: 223589416

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fad140b473586531b5b12843f942ec27dfcf5e93 by CJ Johnson <johnsoncj@google.com>:

Makes unifies the order of forward_iterator and input_iterator overloads

PiperOrigin-RevId: 223580660

--
6cd7c96faa7cc5f79f574e35a1b13837ef187d05 by Abseil Team <absl-team@google.com>:

Internal Change.

PiperOrigin-RevId: 223561629

--
bd2e545356b0f548af0e3c14bb2f7f0e712e49d0 by Shaindel Schwartz <shaindel@google.com>:

Remove misleading comments. try_emplace() does not exist for the hash_set containers.

PiperOrigin-RevId: 223543089

--
0cd380a53b587eb7aacc4003a4a3bbb6c78d7c10 by Derek Mauro <dmauro@google.com>:

Internal change

PiperOrigin-RevId: 223512551

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7156dfee599cb72e9adddfe0e6ae07a95ddf10bb by Greg Miller <jgm@google.com>:

Fixes UB that would result from constructing, multiplying, or dividing a
Duration with a double "NaN" value. This CL changes the absl::Duration
*implementation* to return an InfiniteDuration value that has the same sign as
the given NaN.

PiperOrigin-RevId: 223407499

--
196b7d18609958267951882baf7f9429e49bcafa by CJ Johnson <johnsoncj@google.com>:

Addresses NVCC+MSVC compilation bug where `inlined_capacity()` was not considered valid in constexpr

PiperOrigin-RevId: 223397718
GitOrigin-RevId: cd076f55c1fa600131f6dda392533dfe61679fc0
Change-Id: I5423ca6470f661a7c6f73aa8fee49990446f157f

2 files changed, 23 insertions, 16 deletions

diff --git a/absl/types/internal/variant.h b/absl/types/internal/variant.h
index eff4fefe..477e5895 100644
--- a/absl/types/internal/variant.h
+++ b/absl/types/internal/variant.h
@@ -15,6 +15,7 @@
 // Implementation details of absl/types/variant.h, pulled into a
 // separate file to avoid cluttering the top of the API header with
 // implementation details.
+//
 
 #ifndef ABSL_TYPES_variant_internal_H_
 #define ABSL_TYPES_variant_internal_H_
@@ -1234,23 +1235,29 @@ using VariantCopyBase = absl::conditional_t<
 // Base that is dependent on whether or not the move-assign can be trivial.
 template <class... T>
 using VariantMoveAssignBase = absl::conditional_t<
-    absl::disjunction<absl::conjunction<absl::is_move_assignable<Union<T...>>,
-                                        std::is_move_constructible<Union<T...>>,
-                                        std::is_destructible<Union<T...>>>,
-                      absl::negation<absl::conjunction<
-                          std::is_move_constructible<T>...,
-                          absl::is_move_assignable<T>...>>>::value,
+    absl::disjunction<
+        absl::conjunction<absl::is_move_assignable<Union<T...>>,
+                          std::is_move_constructible<Union<T...>>,
+                          std::is_destructible<Union<T...>>>,
+        absl::negation<absl::conjunction<std::is_move_constructible<T>...,
+                                         // Note: We're not qualifying this with
+                                         // absl:: because it doesn't compile
+                                         // under MSVC.
+                                         is_move_assignable<T>...>>>::value,
     VariantCopyBase<T...>, VariantMoveAssignBaseNontrivial<T...>>;
 
 // Base that is dependent on whether or not the copy-assign can be trivial.
 template <class... T>
 using VariantCopyAssignBase = absl::conditional_t<
-    absl::disjunction<absl::conjunction<absl::is_copy_assignable<Union<T...>>,
-                                        std::is_copy_constructible<Union<T...>>,
-                                        std::is_destructible<Union<T...>>>,
-                      absl::negation<absl::conjunction<
-                          std::is_copy_constructible<T>...,
-                          absl::is_copy_assignable<T>...>>>::value,
+    absl::disjunction<
+        absl::conjunction<absl::is_copy_assignable<Union<T...>>,
+                          std::is_copy_constructible<Union<T...>>,
+                          std::is_destructible<Union<T...>>>,
+        absl::negation<absl::conjunction<std::is_copy_constructible<T>...,
+                                         // Note: We're not qualifying this with
+                                         // absl:: because it doesn't compile
+                                         // under MSVC.
+                                         is_copy_assignable<T>...>>>::value,
     VariantMoveAssignBase<T...>, VariantCopyAssignBaseNontrivial<T...>>;
 
 template <class... T>
diff --git a/absl/types/variant.h b/absl/types/variant.h
index 28aaef4f..48c5d7bf 100644
--- a/absl/types/variant.h
+++ b/absl/types/variant.h
@@ -82,7 +82,7 @@ namespace absl {
 // absl::variant
 // -----------------------------------------------------------------------------
 //
-// An 'absl::variant` type is a form of type-safe union. An `absl::variant` --
+// An `absl::variant` type is a form of type-safe union. An `absl::variant` --
 // except in exceptional cases -- always holds a value of one of its alternative
 // types.
 //
@@ -136,7 +136,7 @@ void swap(variant<Ts...>& v, variant<Ts...>& w) noexcept(noexcept(v.swap(w))) {
 
 // variant_size
 //
-// Returns the number of alterative types available for a given `absl::variant`
+// Returns the number of alternative types available for a given `absl::variant`
 // type as a compile-time constant expression. As this is a class template, it
 // is not generally useful for accessing the number of alternative types of
 // any given `absl::variant` instance.
@@ -454,7 +454,7 @@ class variant<T0, Tn...> : private variant_internal::VariantBase<T0, Tn...> {
                                   std::is_object<Tn>...>::value,
                 "Attempted to instantiate a variant containing a non-object "
                 "type.");
-  // Intentionally not qualifing `negation` with `absl::` to work around a bug
+  // Intentionally not qualifying `negation` with `absl::` to work around a bug
   // in MSVC 2015 with inline namespace and variadic template.
   static_assert(absl::conjunction<negation<std::is_array<T0> >,
                                   negation<std::is_array<Tn> >...>::value,
@@ -562,7 +562,7 @@ class variant<T0, Tn...> : private variant_internal::VariantBase<T0, Tn...> {
 
   // Assignment Operators
 
-  // Copy assignement operator
+  // Copy assignment operator
   variant& operator=(const variant& other) = default;
 
   // Move assignment operator