diff options
Diffstat (limited to 'absl/functional/any_invocable.h')
| -rw-r--r-- | absl/functional/any_invocable.h | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/absl/functional/any_invocable.h b/absl/functional/any_invocable.h index 0c5faca0..68d88253 100644 --- a/absl/functional/any_invocable.h +++ b/absl/functional/any_invocable.h @@ -26,6 +26,9 @@ // NOTE: `absl::AnyInvocable` is similar to the C++23 `std::move_only_function` // abstraction, but has a slightly different API and is not designed to be a // drop-in replacement or C++11-compatible backfill of that type. +// +// Credits to Matt Calabrese (https://github.com/mattcalabrese) for the original +// implementation. #ifndef ABSL_FUNCTIONAL_ANY_INVOCABLE_H_ #define ABSL_FUNCTIONAL_ANY_INVOCABLE_H_ @@ -146,8 +149,8 @@ ABSL_NAMESPACE_BEGIN // std::move(continuation)(result_of_foo); // } // -// Credits to Matt Calabrese (https://github.com/mattcalabrese) for the original -// implementation. +// Attempting to call `absl::AnyInvocable` multiple times in such a case +// results in undefined behavior. template <class Sig> class AnyInvocable : private internal_any_invocable::Impl<Sig> { private: @@ -263,9 +266,17 @@ class AnyInvocable : private internal_any_invocable::Impl<Sig> { // Exchanges the targets of `*this` and `other`. void swap(AnyInvocable& other) noexcept { std::swap(*this, other); } - // abl::AnyInvocable::operator bool() + // absl::AnyInvocable::operator bool() // // Returns `true` if `*this` is not empty. + // + // WARNING: An `AnyInvocable` that wraps an empty `std::function` is not + // itself empty. This behavior is consistent with the standard equivalent + // `std::move_only_function`. + // + // In other words: + // std::function<void()> f; // empty + // absl::AnyInvocable<void()> a = std::move(f); // not empty explicit operator bool() const noexcept { return this->HasValue(); } // Invokes the target object of `*this`. `*this` must not be empty. |