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// Copyright 2019 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "absl/functional/function_ref.h"
#include <functional>
#include <memory>
#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 {
ABSL_NAMESPACE_BEGIN
namespace {
void RunFun(FunctionRef<void()> f) { f(); }
TEST(FunctionRefTest, Lambda) {
bool ran = false;
RunFun([&] { ran = true; });
EXPECT_TRUE(ran);
}
int Function() { return 1337; }
TEST(FunctionRefTest, Function1) {
FunctionRef<int()> ref(&Function);
EXPECT_EQ(1337, ref());
}
TEST(FunctionRefTest, Function2) {
FunctionRef<int()> ref(Function);
EXPECT_EQ(1337, ref());
}
TEST(FunctionRefTest, ConstFunction) {
FunctionRef<int() const> ref(Function);
EXPECT_EQ(1337, ref());
}
int NoExceptFunction() noexcept { return 1337; }
// TODO(jdennett): Add a test for noexcept member functions.
TEST(FunctionRefTest, NoExceptFunction) {
FunctionRef<int()> ref(NoExceptFunction);
EXPECT_EQ(1337, ref());
}
TEST(FunctionRefTest, ForwardsArgs) {
auto l = [](std::unique_ptr<int> i) { return *i; };
FunctionRef<int(std::unique_ptr<int>)> ref(l);
EXPECT_EQ(42, ref(absl::make_unique<int>(42)));
}
TEST(FunctionRef, ReturnMoveOnly) {
auto l = [] { return absl::make_unique<int>(29); };
FunctionRef<std::unique_ptr<int>()> ref(l);
EXPECT_EQ(29, *ref());
}
TEST(FunctionRef, ManyArgs) {
auto l = [](int a, int b, int c) { return a + b + c; };
FunctionRef<int(int, int, int)> ref(l);
EXPECT_EQ(6, ref(1, 2, 3));
}
TEST(FunctionRef, VoidResultFromNonVoidFunctor) {
bool ran = false;
auto l = [&]() -> int {
ran = true;
return 2;
};
FunctionRef<void()> ref(l);
ref();
EXPECT_TRUE(ran);
}
TEST(FunctionRef, CastFromDerived) {
struct Base {};
struct Derived : public Base {};
Derived d;
auto l1 = [&](Base* b) { EXPECT_EQ(&d, b); };
FunctionRef<void(Derived*)> ref1(l1);
ref1(&d);
auto l2 = [&]() -> Derived* { return &d; };
FunctionRef<Base*()> ref2(l2);
EXPECT_EQ(&d, ref2());
}
TEST(FunctionRef, VoidResultFromNonVoidFuncton) {
FunctionRef<void()> ref(Function);
ref();
}
TEST(FunctionRef, MemberPtr) {
struct S {
int i;
};
S s{1100111};
auto mem_ptr = &S::i;
FunctionRef<int(const S& s)> ref(mem_ptr);
EXPECT_EQ(1100111, ref(s));
}
TEST(FunctionRef, MemberFun) {
struct S {
int i;
int get_i() const { return i; }
};
S s{22};
auto mem_fun_ptr = &S::get_i;
FunctionRef<int(const S& s)> ref(mem_fun_ptr);
EXPECT_EQ(22, ref(s));
}
TEST(FunctionRef, MemberFunRefqualified) {
struct S {
int i;
int get_i() && { return i; }
};
auto mem_fun_ptr = &S::get_i;
S s{22};
FunctionRef<int(S && s)> ref(mem_fun_ptr);
EXPECT_EQ(22, ref(std::move(s)));
}
#if !defined(_WIN32) && defined(GTEST_HAS_DEATH_TEST)
TEST(FunctionRef, MemberFunRefqualifiedNull) {
struct S {
int i;
int get_i() && { return i; }
};
auto mem_fun_ptr = &S::get_i;
mem_fun_ptr = nullptr;
EXPECT_DEBUG_DEATH({ FunctionRef<int(S && s)> ref(mem_fun_ptr); }, "");
}
TEST(FunctionRef, NullMemberPtrAssertFails) {
struct S {
int i;
};
using MemberPtr = int S::*;
MemberPtr mem_ptr = nullptr;
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) {
absl::test_internal::InstanceTracker tracker;
absl::test_internal::CopyableMovableInstance instance(0);
auto l = [](absl::test_internal::CopyableMovableInstance) {};
FunctionRef<void(absl::test_internal::CopyableMovableInstance)> ref(l);
ref(instance);
EXPECT_EQ(tracker.copies(), 1);
EXPECT_EQ(tracker.moves(), 1);
}
TEST(FunctionRef, CopiesAndMovesPerPassByRef) {
absl::test_internal::InstanceTracker tracker;
absl::test_internal::CopyableMovableInstance instance(0);
auto l = [](const absl::test_internal::CopyableMovableInstance&) {};
FunctionRef<void(const absl::test_internal::CopyableMovableInstance&)> ref(l);
ref(instance);
EXPECT_EQ(tracker.copies(), 0);
EXPECT_EQ(tracker.moves(), 0);
}
TEST(FunctionRef, CopiesAndMovesPerPassByValueCallByMove) {
absl::test_internal::InstanceTracker tracker;
absl::test_internal::CopyableMovableInstance instance(0);
auto l = [](absl::test_internal::CopyableMovableInstance) {};
FunctionRef<void(absl::test_internal::CopyableMovableInstance)> ref(l);
ref(std::move(instance));
EXPECT_EQ(tracker.copies(), 0);
EXPECT_EQ(tracker.moves(), 2);
}
TEST(FunctionRef, CopiesAndMovesPerPassByValueToRef) {
absl::test_internal::InstanceTracker tracker;
absl::test_internal::CopyableMovableInstance instance(0);
auto l = [](const absl::test_internal::CopyableMovableInstance&) {};
FunctionRef<void(absl::test_internal::CopyableMovableInstance)> ref(l);
ref(std::move(instance));
EXPECT_EQ(tracker.copies(), 0);
EXPECT_EQ(tracker.moves(), 1);
}
TEST(FunctionRef, PassByValueTypes) {
using absl::functional_internal::Invoker;
using absl::functional_internal::VoidPtr;
using absl::test_internal::CopyableMovableInstance;
struct Trivial {
void* p[2];
};
struct LargeTrivial {
void* p[3];
};
static_assert(std::is_same<Invoker<void, int>, void (*)(VoidPtr, int)>::value,
"Scalar types should be passed by value");
static_assert(
std::is_same<Invoker<void, Trivial>, void (*)(VoidPtr, Trivial)>::value,
"Small trivial types should be passed by value");
static_assert(std::is_same<Invoker<void, LargeTrivial>,
void (*)(VoidPtr, LargeTrivial &&)>::value,
"Large trivial types should be passed by rvalue reference");
static_assert(
std::is_same<Invoker<void, CopyableMovableInstance>,
void (*)(VoidPtr, CopyableMovableInstance &&)>::value,
"Types with copy/move ctor should be passed by rvalue reference");
// References are passed as references.
static_assert(
std::is_same<Invoker<void, int&>, void (*)(VoidPtr, int&)>::value,
"Reference types should be preserved");
static_assert(
std::is_same<Invoker<void, CopyableMovableInstance&>,
void (*)(VoidPtr, CopyableMovableInstance&)>::value,
"Reference types should be preserved");
static_assert(
std::is_same<Invoker<void, CopyableMovableInstance&&>,
void (*)(VoidPtr, CopyableMovableInstance &&)>::value,
"Reference types should be preserved");
// Make sure the address of an object received by reference is the same as the
// address of the object passed by the caller.
{
LargeTrivial obj;
auto test = [&obj](LargeTrivial& input) { ASSERT_EQ(&input, &obj); };
absl::FunctionRef<void(LargeTrivial&)> ref(test);
ref(obj);
}
{
Trivial obj;
auto test = [&obj](Trivial& input) { ASSERT_EQ(&input, &obj); };
absl::FunctionRef<void(Trivial&)> ref(test);
ref(obj);
}
}
TEST(FunctionRef, ReferenceToIncompleteType) {
struct IncompleteType;
auto test = [](IncompleteType&) {};
absl::FunctionRef<void(IncompleteType&)> ref(test);
struct IncompleteType {};
IncompleteType obj;
ref(obj);
}
} // namespace
ABSL_NAMESPACE_END
} // namespace absl