From dc44b95ab0cc988afd225d0eb9f7021f96fcd2b6 Mon Sep 17 00:00:00 2001
From: Abseil Team <absl-team@google.com>
Date: Mon, 6 Mar 2023 10:26:02 -0800
Subject: Support lvalue references to incomplete types as `FunctionRef`
 parameters.

PiperOrigin-RevId: 514451518
Change-Id: Ic1391374c7bff08ba437ac0410631d1f701bb9ed
---
 absl/functional/internal/function_ref.h | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

(limited to 'absl/functional/internal/function_ref.h')

diff --git a/absl/functional/internal/function_ref.h b/absl/functional/internal/function_ref.h
index b5bb8b43..a1ddbb0c 100644
--- a/absl/functional/internal/function_ref.h
+++ b/absl/functional/internal/function_ref.h
@@ -40,18 +40,21 @@ union VoidPtr {
 // Chooses the best type for passing T as an argument.
 // Attempt to be close to SystemV AMD64 ABI. Objects with trivial copy ctor are
 // passed by value.
+template <typename T,
+          bool IsLValueReference = std::is_lvalue_reference<T>::value>
+struct PassByValue : std::false_type {};
+
 template <typename T>
-constexpr bool PassByValue() {
-  return !std::is_lvalue_reference<T>::value &&
-         absl::is_trivially_copy_constructible<T>::value &&
-         absl::is_trivially_copy_assignable<
-             typename std::remove_cv<T>::type>::value &&
-         std::is_trivially_destructible<T>::value &&
-         sizeof(T) <= 2 * sizeof(void*);
-}
+struct PassByValue<T, /*IsLValueReference=*/false>
+    : std::integral_constant<bool,
+                             absl::is_trivially_copy_constructible<T>::value &&
+                                 absl::is_trivially_copy_assignable<
+                                     typename std::remove_cv<T>::type>::value &&
+                                 std::is_trivially_destructible<T>::value &&
+                                 sizeof(T) <= 2 * sizeof(void*)> {};
 
 template <typename T>
-struct ForwardT : std::conditional<PassByValue<T>(), T, T&&> {};
+struct ForwardT : std::conditional<PassByValue<T>::value, T, T&&> {};
 
 // An Invoker takes a pointer to the type-erased invokable object, followed by
 // the arguments that the invokable object expects.
-- 
cgit v1.2.3


From 8bd7178b14ea61972f8b04e9a9352bc4a4666cfb Mon Sep 17 00:00:00 2001
From: Abseil Team <absl-team@google.com>
Date: Mon, 24 Apr 2023 08:04:04 -0700
Subject:     Adds template specialization for nullptr assertion of
 absl::AnyInvocable types.

PiperOrigin-RevId: 526644558
Change-Id: I050162c2c0d667c32f7e11f51201054cca52667d
---
 absl/functional/BUILD.bazel             |  2 ++
 absl/functional/CMakeLists.txt          |  1 +
 absl/functional/function_ref_test.cc    | 20 ++++++++++++++++++++
 absl/functional/internal/function_ref.h |  7 +++++++
 4 files changed, 30 insertions(+)

(limited to 'absl/functional/internal/function_ref.h')

diff --git a/absl/functional/BUILD.bazel b/absl/functional/BUILD.bazel
index c4fbce98..4ceac539 100644
--- a/absl/functional/BUILD.bazel
+++ b/absl/functional/BUILD.bazel
@@ -92,6 +92,7 @@ cc_library(
     copts = ABSL_DEFAULT_COPTS,
     linkopts = ABSL_DEFAULT_LINKOPTS,
     deps = [
+        ":any_invocable",
         "//absl/base:base_internal",
         "//absl/base:core_headers",
         "//absl/meta:type_traits",
@@ -104,6 +105,7 @@ cc_test(
     srcs = ["function_ref_test.cc"],
     copts = ABSL_TEST_COPTS,
     deps = [
+        ":any_invocable",
         ":function_ref",
         "//absl/container:test_instance_tracker",
         "//absl/memory",
diff --git a/absl/functional/CMakeLists.txt b/absl/functional/CMakeLists.txt
index c0f6eaaa..628b2ffc 100644
--- a/absl/functional/CMakeLists.txt
+++ b/absl/functional/CMakeLists.txt
@@ -90,6 +90,7 @@ absl_cc_library(
   DEPS
     absl::base_internal
     absl::core_headers
+    absl::any_invocable
     absl::meta
   PUBLIC
 )
diff --git a/absl/functional/function_ref_test.cc b/absl/functional/function_ref_test.cc
index d0923fdd..f91e15e0 100644
--- a/absl/functional/function_ref_test.cc
+++ b/absl/functional/function_ref_test.cc
@@ -20,6 +20,7 @@
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 #include "absl/container/internal/test_instance_tracker.h"
+#include "absl/functional/any_invocable.h"
 #include "absl/memory/memory.h"
 
 namespace absl {
@@ -157,6 +158,25 @@ TEST(FunctionRef, NullMemberPtrAssertFails) {
   EXPECT_DEBUG_DEATH({ FunctionRef<int(const S& s)> ref(mem_ptr); }, "");
 }
 
+TEST(FunctionRef, NullStdFunctionAssertPasses) {
+  std::function<void()> function = []() {};
+  FunctionRef<void()> ref(function);
+}
+
+TEST(FunctionRef, NullStdFunctionAssertFails) {
+  std::function<void()> function = nullptr;
+  EXPECT_DEBUG_DEATH({ FunctionRef<void()> ref(function); }, "");
+}
+
+TEST(FunctionRef, NullAnyInvocableAssertPasses) {
+  AnyInvocable<void() const> invocable = []() {};
+  FunctionRef<void()> ref(invocable);
+}
+TEST(FunctionRef, NullAnyInvocableAssertFails) {
+  AnyInvocable<void() const> invocable = nullptr;
+  EXPECT_DEBUG_DEATH({ FunctionRef<void()> ref(invocable); }, "");
+}
+
 #endif  // GTEST_HAS_DEATH_TEST
 
 TEST(FunctionRef, CopiesAndMovesPerPassByValue) {
diff --git a/absl/functional/internal/function_ref.h b/absl/functional/internal/function_ref.h
index a1ddbb0c..1cd34a3c 100644
--- a/absl/functional/internal/function_ref.h
+++ b/absl/functional/internal/function_ref.h
@@ -20,6 +20,7 @@
 #include <type_traits>
 
 #include "absl/base/internal/invoke.h"
+#include "absl/functional/any_invocable.h"
 #include "absl/meta/type_traits.h"
 
 namespace absl {
@@ -90,6 +91,12 @@ void AssertNonNull(const std::function<Sig>& f) {
   (void)f;
 }
 
+template <typename Sig>
+void AssertNonNull(const AnyInvocable<Sig>& f) {
+  assert(f != nullptr);
+  (void)f;
+}
+
 template <typename F>
 void AssertNonNull(const F&) {}
 
-- 
cgit v1.2.3