Export of internal Abseil changes.

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8becce38c862a044db194a9aea1b505796a46d6f by Abseil Team <absl-team@google.com>:

Updates the FixedArray's constructors to be exception safe by preventing double deletions. Also adds exception safety tests for FixedArray to document/enforce the expected behavior.

PiperOrigin-RevId: 201964431

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794188b401a602b4be97190fb8738066fe1f9ca5 by Derek Mauro <dmauro@google.com>:

Fixes for str_format.h documentation.

PiperOrigin-RevId: 201951760

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beae3bdd6eee2cf61101102fddc35ada188f330b by Alex Strelnikov <strel@google.com>:

Add numeric_limits specialization for uint128.

Turns out numeric_limits is a case where the consensus is that it is okay to specialize for a user defined type.

PiperOrigin-RevId: 201944736

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b2b3444a52b36878ade1ae8801e69932b05fc4f9 by Shaindel Schwartz <shaindel@google.com>:

Internal change.

PiperOrigin-RevId: 201718662

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aa924c459922f39caabfc193998c58d0f4981ac0 by Abseil Team <absl-team@google.com>:

Typo fix.

PiperOrigin-RevId: 201692176

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bbfcaa7b1af331d9b97c92470608240c5c864fbc by Xiaoyi Zhang <zhangxy@google.com>:

Use ABSL_HAVE_ANY/OPTIONAL/VARIANT to conditionally compile out the definition of absl::bad_any_cast, absl::bad_optional_access, absl::bad_variant_access. This would fix the issues where users #include those header directly in C++17 modes.

PiperOrigin-RevId: 201683792
GitOrigin-RevId: 8becce38c862a044db194a9aea1b505796a46d6f
Change-Id: I60a7ad043136a439d82c374d225a1804016b0509

3 files changed, 90 insertions, 5 deletions

diff --git a/absl/numeric/int128.cc b/absl/numeric/int128.cc
index 3688e5ef..cd79534f 100644
--- a/absl/numeric/int128.cc
+++ b/absl/numeric/int128.cc
@@ -223,3 +223,29 @@ std::ostream& operator<<(std::ostream& os, uint128 v) {
 }
 
 }  // namespace absl
+
+namespace std {
+constexpr bool numeric_limits<absl::uint128>::is_specialized;
+constexpr bool numeric_limits<absl::uint128>::is_signed;
+constexpr bool numeric_limits<absl::uint128>::is_integer;
+constexpr bool numeric_limits<absl::uint128>::is_exact;
+constexpr bool numeric_limits<absl::uint128>::has_infinity;
+constexpr bool numeric_limits<absl::uint128>::has_quiet_NaN;
+constexpr bool numeric_limits<absl::uint128>::has_signaling_NaN;
+constexpr float_denorm_style numeric_limits<absl::uint128>::has_denorm;
+constexpr bool numeric_limits<absl::uint128>::has_denorm_loss;
+constexpr float_round_style numeric_limits<absl::uint128>::round_style;
+constexpr bool numeric_limits<absl::uint128>::is_iec559;
+constexpr bool numeric_limits<absl::uint128>::is_bounded;
+constexpr bool numeric_limits<absl::uint128>::is_modulo;
+constexpr int numeric_limits<absl::uint128>::digits;
+constexpr int numeric_limits<absl::uint128>::digits10;
+constexpr int numeric_limits<absl::uint128>::max_digits10;
+constexpr int numeric_limits<absl::uint128>::radix;
+constexpr int numeric_limits<absl::uint128>::min_exponent;
+constexpr int numeric_limits<absl::uint128>::min_exponent10;
+constexpr int numeric_limits<absl::uint128>::max_exponent;
+constexpr int numeric_limits<absl::uint128>::max_exponent10;
+constexpr bool numeric_limits<absl::uint128>::traps;
+constexpr bool numeric_limits<absl::uint128>::tinyness_before;
+}  // namespace std
diff --git a/absl/numeric/int128.h b/absl/numeric/int128.h
index bc7dbb47..e4f39c30 100644
--- a/absl/numeric/int128.h
+++ b/absl/numeric/int128.h
@@ -219,21 +219,69 @@ std::ostream& operator<<(std::ostream& os, uint128 v);
 
 // TODO(strel) add operator>>(std::istream&, uint128)
 
+constexpr uint128 Uint128Max() {
+  return uint128(std::numeric_limits<uint64_t>::max(),
+                 std::numeric_limits<uint64_t>::max());
+}
+
+}  // namespace absl
+
+// Specialized numeric_limits for uint128.
+namespace std {
+template <>
+class numeric_limits<absl::uint128> {
+ public:
+  static constexpr bool is_specialized = true;
+  static constexpr bool is_signed = false;
+  static constexpr bool is_integer = true;
+  static constexpr bool is_exact = true;
+  static constexpr bool has_infinity = false;
+  static constexpr bool has_quiet_NaN = false;
+  static constexpr bool has_signaling_NaN = false;
+  static constexpr float_denorm_style has_denorm = denorm_absent;
+  static constexpr bool has_denorm_loss = false;
+  static constexpr float_round_style round_style = round_toward_zero;
+  static constexpr bool is_iec559 = false;
+  static constexpr bool is_bounded = true;
+  static constexpr bool is_modulo = true;
+  static constexpr int digits = 128;
+  static constexpr int digits10 = 38;
+  static constexpr int max_digits10 = 0;
+  static constexpr int radix = 2;
+  static constexpr int min_exponent = 0;
+  static constexpr int min_exponent10 = 0;
+  static constexpr int max_exponent = 0;
+  static constexpr int max_exponent10 = 0;
+#ifdef ABSL_HAVE_INTRINSIC_INT128
+  static constexpr bool traps = numeric_limits<unsigned __int128>::traps;
+#else   // ABSL_HAVE_INTRINSIC_INT128
+  static constexpr bool traps = numeric_limits<uint64_t>::traps;
+#endif  // ABSL_HAVE_INTRINSIC_INT128
+  static constexpr bool tinyness_before = false;
+
+  static constexpr absl::uint128 min() { return 0; }
+  static constexpr absl::uint128 lowest() { return 0; }
+  static constexpr absl::uint128 max() { return absl::Uint128Max(); }
+  static constexpr absl::uint128 epsilon() { return 0; }
+  static constexpr absl::uint128 round_error() { return 0; }
+  static constexpr absl::uint128 infinity() { return 0; }
+  static constexpr absl::uint128 quiet_NaN() { return 0; }
+  static constexpr absl::uint128 signaling_NaN() { return 0; }
+  static constexpr absl::uint128 denorm_min() { return 0; }
+};
+}  // namespace std
+
 // TODO(absl-team): Implement signed 128-bit type
 
 // --------------------------------------------------------------------------
 //                      Implementation details follow
 // --------------------------------------------------------------------------
+namespace absl {
 
 constexpr uint128 MakeUint128(uint64_t high, uint64_t low) {
   return uint128(high, low);
 }
 
-constexpr uint128 Uint128Max() {
-  return uint128(std::numeric_limits<uint64_t>::max(),
-                 std::numeric_limits<uint64_t>::max());
-}
-
 // Assignment from integer types.
 
 inline uint128& uint128::operator=(int v) { return *this = uint128(v); }
diff --git a/absl/numeric/int128_test.cc b/absl/numeric/int128_test.cc
index 79bcca90..1eb3e0ec 100644
--- a/absl/numeric/int128_test.cc
+++ b/absl/numeric/int128_test.cc
@@ -428,4 +428,15 @@ TEST(Uint128, ConstexprTest) {
   EXPECT_EQ(minus_two, absl::MakeUint128(-1, -2));
 }
 
+TEST(Uint128, NumericLimitsTest) {
+  static_assert(std::numeric_limits<absl::uint128>::is_specialized, "");
+  static_assert(!std::numeric_limits<absl::uint128>::is_signed, "");
+  static_assert(std::numeric_limits<absl::uint128>::is_integer, "");
+  EXPECT_EQ(static_cast<int>(128 * std::log10(2)),
+            std::numeric_limits<absl::uint128>::digits10);
+  EXPECT_EQ(0, std::numeric_limits<absl::uint128>::min());
+  EXPECT_EQ(0, std::numeric_limits<absl::uint128>::lowest());
+  EXPECT_EQ(absl::Uint128Max(), std::numeric_limits<absl::uint128>::max());
+}
+
 }  // namespace