Merge new upstream LTS 20240722.0

1 files changed, 13 insertions, 3 deletions

diff --git a/absl/functional/any_invocable.h b/absl/functional/any_invocable.h
index 68d88253..3acb9fd0 100644
--- a/absl/functional/any_invocable.h
+++ b/absl/functional/any_invocable.h
@@ -34,6 +34,7 @@
 #define ABSL_FUNCTIONAL_ANY_INVOCABLE_H_
 
 #include <cstddef>
+#include <functional>
 #include <initializer_list>
 #include <type_traits>
 #include <utility>
@@ -98,9 +99,9 @@ ABSL_NAMESPACE_BEGIN
 // `AnyInvocable` also properly respects `const` qualifiers, reference
 // qualifiers, and the `noexcept` specification (only in C++ 17 and beyond) as
 // part of the user-specified function type (e.g.
-// `AnyInvocable<void()&& const noexcept>`). These qualifiers will be applied to
-// the `AnyInvocable` object's `operator()`, and the underlying invocable must
-// be compatible with those qualifiers.
+// `AnyInvocable<void() const && noexcept>`). These qualifiers will be applied
+// to the `AnyInvocable` object's `operator()`, and the underlying invocable
+// must be compatible with those qualifiers.
 //
 // Comparison of const and non-const function types:
 //
@@ -151,6 +152,12 @@ ABSL_NAMESPACE_BEGIN
 //
 // Attempting to call `absl::AnyInvocable` multiple times in such a case
 // results in undefined behavior.
+//
+// Invoking an empty `absl::AnyInvocable` results in undefined behavior:
+//
+//   // Create an empty instance using the default constructor.
+//   AnyInvocable<void()> empty;
+//   empty();  // WARNING: Undefined behavior!
 template <class Sig>
 class AnyInvocable : private internal_any_invocable::Impl<Sig> {
  private:
@@ -167,6 +174,7 @@ class AnyInvocable : private internal_any_invocable::Impl<Sig> {
   // Constructors
 
   // Constructs the `AnyInvocable` in an empty state.
+  // Invoking it results in undefined behavior.
   AnyInvocable() noexcept = default;
   AnyInvocable(std::nullptr_t) noexcept {}  // NOLINT
 
@@ -277,6 +285,8 @@ class AnyInvocable : private internal_any_invocable::Impl<Sig> {
   // In other words:
   //   std::function<void()> f;  // empty
   //   absl::AnyInvocable<void()> a = std::move(f);  // not empty
+  //
+  // Invoking an empty `AnyInvocable` results in undefined behavior.
   explicit operator bool() const noexcept { return this->HasValue(); }
 
   // Invokes the target object of `*this`. `*this` must not be empty.