diff --git a/README.md b/README.md
index 2d78e46db..c6db64ab4 100644
--- a/README.md
+++ b/README.md
@@ -67,7 +67,7 @@ Abseil contains the following C++ library components:
time zones.
* [`types`](absl/types/)
The `types` library contains non-container utility types, like a
- C++11-compatible version of `absl::optional`.
+ C++11-compatible version of the C++17 `std::optional` type.
## License
diff --git a/absl/base/config.h b/absl/base/config.h
index 4aff49237..5f0dd04c8 100644
--- a/absl/base/config.h
+++ b/absl/base/config.h
@@ -180,7 +180,7 @@
#ifdef ABSL_HAVE_INTRINSIC_INT128
#error ABSL_HAVE_INTRINSIC_INT128 cannot be directly set
#elif (defined(__clang__) && defined(__SIZEOF_INT128__) && \
- !defined(__ppc64__) && !defined(__aarch64__)) || \
+ !defined(__aarch64__)) || \
(defined(__CUDACC__) && defined(__SIZEOF_INT128__) && \
__CUDACC_VER__ >= 70000) || \
(!defined(__clang__) && !defined(__CUDACC__) && defined(__GNUC__) && \
diff --git a/absl/container/inlined_vector.h b/absl/container/inlined_vector.h
index f060f5c5c..f68ca5074 100644
--- a/absl/container/inlined_vector.h
+++ b/absl/container/inlined_vector.h
@@ -124,9 +124,24 @@ class InlinedVector {
InlinedVector(const InlinedVector& v);
InlinedVector(const InlinedVector& v, const allocator_type& alloc);
+ // This move constructor does not allocate and only moves the underlying
+ // objects, so its `noexcept` specification depends on whether moving the
+ // underlying objects can throw or not. We assume
+ // a) move constructors should only throw due to allocation failure and
+ // b) if `value_type`'s move constructor allocates, it uses the same
+ // allocation function as the `InlinedVector`'s allocator, so the move
+ // constructor is non-throwing if the allocator is non-throwing or
+ // `value_type`'s move constructor is specified as `noexcept`.
InlinedVector(InlinedVector&& v) noexcept(
absl::allocator_is_nothrow::value ||
std::is_nothrow_move_constructible::value);
+
+ // This move constructor allocates and also moves the underlying objects, so
+ // its `noexcept` specification depends on whether the allocation can throw
+ // and whether moving the underlying objects can throw. Based on the same
+ // assumptions above, the `noexcept` specification is dominated by whether the
+ // allocation can throw regardless of whether `value_type`'s move constructor
+ // is specified as `noexcept`.
InlinedVector(InlinedVector&& v, const allocator_type& alloc) noexcept(
absl::allocator_is_nothrow::value);
diff --git a/absl/meta/type_traits.h b/absl/meta/type_traits.h
index ced66269b..6f7138c2d 100644
--- a/absl/meta/type_traits.h
+++ b/absl/meta/type_traits.h
@@ -135,8 +135,11 @@ struct negation : std::integral_constant {};
//
// Determines whether the passed type `T` is trivially destructable.
//
-// This metafunction is designed to be a drop-in replacement for the C++17
-// `std::is_trivially_destructible()` metafunction.
+// This metafunction is designed to be a drop-in replacement for the C++11
+// `std::is_trivially_destructible()` metafunction for platforms that have
+// incomplete C++11 support (such as libstdc++ 4.x). On any platforms that do
+// fully support C++11, we check whether this yields the same result as the std
+// implementation.
//
// NOTE: the extensions (__has_trivial_xxx) are implemented in gcc (version >=
// 4.3) and clang. Since we are supporting libstdc++ > 4.7, they should always
@@ -157,8 +160,11 @@ struct is_trivially_destructible
//
// Determines whether the passed type `T` is trivially default constructible.
//
-// This metafunction is designed to be a drop-in replacement for the C++17
-// `std::is_trivially_default_constructible()` metafunction.
+// This metafunction is designed to be a drop-in replacement for the C++11
+// `std::is_trivially_default_constructible()` metafunction for platforms that
+// have incomplete C++11 support (such as libstdc++ 4.x). On any platforms that
+// do fully support C++11, we check whether this yields the same result as the
+// std implementation.
//
// NOTE: according to the C++ standard, Section: 20.15.4.3 [meta.unary.prop]
// "The predicate condition for a template specialization is_constructible());` needs to be well-formed and not call any
// nontrivial operation. Nontrivally destructible types will cause the
@@ -221,8 +230,11 @@ struct is_trivially_copy_constructible
//
// Determines whether the passed type `T` is trivially copy assignable.
//
-// This metafunction is designed to be a drop-in replacement for the C++17
-// `std::is_trivially_copy_assignable()` metafunction.
+// This metafunction is designed to be a drop-in replacement for the C++11
+// `std::is_trivially_copy_assignable()` metafunction for platforms that have
+// incomplete C++11 support (such as libstdc++ 4.x). On any platforms that do
+// fully support C++11, we check whether this yields the same result as the std
+// implementation.
//
// NOTE: `is_assignable::value` is `true` if the expression
// `declval() = declval()` is well-formed when treated as an unevaluated
diff --git a/absl/strings/str_cat_test.cc b/absl/strings/str_cat_test.cc
index 293d1943b..dd063b015 100644
--- a/absl/strings/str_cat_test.cc
+++ b/absl/strings/str_cat_test.cc
@@ -300,6 +300,12 @@ TEST(StrAppend, Basics) {
"World"
};
+ std::string stdstrs[] = {
+ "std::Hello",
+ "std::Cruel",
+ "std::World"
+ };
+
absl::string_view pieces[] = {"Hello", "Cruel", "World"};
const char* c_strs[] = {
@@ -324,12 +330,12 @@ TEST(StrAppend, Basics) {
EXPECT_EQ(result.substr(old_size), "CruelWorld");
old_size = result.size();
- absl::StrAppend(&result, strs[0], ", ", pieces[2]);
- EXPECT_EQ(result.substr(old_size), "Hello, World");
+ absl::StrAppend(&result, stdstrs[0], ", ", pieces[2]);
+ EXPECT_EQ(result.substr(old_size), "std::Hello, World");
old_size = result.size();
- absl::StrAppend(&result, strs[0], ", ", strs[1], " ", strs[2], "!");
- EXPECT_EQ(result.substr(old_size), "Hello, Cruel World!");
+ absl::StrAppend(&result, strs[0], ", ", stdstrs[1], " ", strs[2], "!");
+ EXPECT_EQ(result.substr(old_size), "Hello, std::Cruel World!");
old_size = result.size();
absl::StrAppend(&result, pieces[0], ", ", pieces[1], " ", pieces[2]);
diff --git a/absl/time/clock_test.cc b/absl/time/clock_test.cc
index 933ed240b..f143c0360 100644
--- a/absl/time/clock_test.cc
+++ b/absl/time/clock_test.cc
@@ -41,7 +41,7 @@ TEST(SleepForTest, BasicSanity) {
absl::SleepFor(sleep_time);
absl::Time end = absl::Now();
EXPECT_LE(sleep_time - absl::Milliseconds(100), end - start);
- EXPECT_GE(sleep_time + absl::Milliseconds(100), end - start);
+ EXPECT_GE(sleep_time + absl::Milliseconds(200), end - start);
}
#ifdef ABSL_HAVE_ALARM
@@ -62,7 +62,7 @@ TEST(SleepForTest, AlarmSupport) {
absl::Time end = absl::Now();
EXPECT_TRUE(alarm_handler_invoked);
EXPECT_LE(sleep_time - absl::Milliseconds(100), end - start);
- EXPECT_GE(sleep_time + absl::Milliseconds(100), end - start);
+ EXPECT_GE(sleep_time + absl::Milliseconds(200), end - start);
signal(SIGALRM, old_alarm);
}
#endif // ABSL_HAVE_ALARM
diff --git a/absl/types/optional.h b/absl/types/optional.h
index f1b41ace8..e952a04aa 100644
--- a/absl/types/optional.h
+++ b/absl/types/optional.h
@@ -118,6 +118,13 @@ namespace absl {
// and `is_nothrow_swappable()` is the same as `std::is_trivial()`.
// * `make_optional()` cannot be declared `constexpr` due to the absence of
// guaranteed copy elision.
+// * The move constructor's `noexcept` specification is stronger, i.e. if the
+// default allocator is non-throwing (via setting
+// `ABSL_ALLOCATOR_NOTHROW`), it evaluates to `noexcept(true)`, because
+// we assume
+// a) move constructors should only throw due to allocation failure and
+// b) if T's move constructor allocates, it uses the same allocation
+// function as the default allocator.
template
class optional;