From c154d20abce2f1ae6bd35bd774313e351493219b Mon Sep 17 00:00:00 2001 From: Benjamin Barenblat Date: Thu, 25 May 2023 10:40:43 -0700 Subject: Split absl/hash/hash_test.cc into two files hash_test.cc leans heavily on INSTANTIATE_TYPED_TEST_SUITE_P, which is quite memory- and CPU-hungry. Split a few heavyweight tests into a new hash_instantiated_test.cc, reducing peak RAM consumption (or, on multicore systems, compilation time). PiperOrigin-RevId: 535305679 Change-Id: Ic204da0a47c749c3f7db5f902ade8d74ed3043bb --- absl/hash/BUILD.bazel | 27 ++++- absl/hash/CMakeLists.txt | 21 ++++ absl/hash/hash_instantiated_test.cc | 224 +++++++++++++++++++++++++++++++++++ absl/hash/hash_test.cc | 228 +----------------------------------- absl/hash/internal/hash_test.h | 87 ++++++++++++++ 5 files changed, 362 insertions(+), 225 deletions(-) create mode 100644 absl/hash/hash_instantiated_test.cc create mode 100644 absl/hash/internal/hash_test.h (limited to 'absl/hash') diff --git a/absl/hash/BUILD.bazel b/absl/hash/BUILD.bazel index a0db919b..7f964ae7 100644 --- a/absl/hash/BUILD.bazel +++ b/absl/hash/BUILD.bazel @@ -68,13 +68,17 @@ cc_library( cc_test( name = "hash_test", - srcs = ["hash_test.cc"], + srcs = [ + "hash_test.cc", + "internal/hash_test.h", + ], copts = ABSL_TEST_COPTS, linkopts = ABSL_DEFAULT_LINKOPTS, deps = [ ":hash", ":hash_testing", ":spy_hash_state", + "//absl/base:config", "//absl/base:core_headers", "//absl/container:btree", "//absl/container:flat_hash_map", @@ -88,6 +92,27 @@ cc_test( ], ) +cc_test( + name = "hash_instantiated_test", + srcs = [ + "hash_instantiated_test.cc", + "internal/hash_test.h", + ], + copts = ABSL_TEST_COPTS, + linkopts = ABSL_DEFAULT_LINKOPTS, + deps = [ + ":hash", + ":hash_testing", + "//absl/base:config", + "//absl/container:btree", + "//absl/container:flat_hash_map", + "//absl/container:flat_hash_set", + "//absl/container:node_hash_map", + "//absl/container:node_hash_set", + "@com_google_googletest//:gtest_main", + ], +) + cc_binary( name = "hash_benchmark", testonly = 1, diff --git a/absl/hash/CMakeLists.txt b/absl/hash/CMakeLists.txt index f99f35bc..1adce617 100644 --- a/absl/hash/CMakeLists.txt +++ b/absl/hash/CMakeLists.txt @@ -64,6 +64,7 @@ absl_cc_test( hash_test SRCS "hash_test.cc" + "internal/hash_test.h" COPTS ${ABSL_TEST_COPTS} DEPS @@ -82,6 +83,26 @@ absl_cc_test( GTest::gmock_main ) +absl_cc_test( + NAME + hash_instantiated_test + SRCS + "hash_test.cc" + "internal/hash_test.h" + COPTS + ${ABSL_TEST_COPTS} + DEPS + absl::hash + absl::hash_testing + absl::config + absl::btree + absl::flat_hash_map + absl::flat_hash_set + absl::node_hash_map + absl::node_hash_set + GTest::gtest_main +) + # Internal-only target, do not depend on directly. # # Note: Even though external code should not depend on this target diff --git a/absl/hash/hash_instantiated_test.cc b/absl/hash/hash_instantiated_test.cc new file mode 100644 index 00000000..e65de9ca --- /dev/null +++ b/absl/hash/hash_instantiated_test.cc @@ -0,0 +1,224 @@ +// Copyright 2018 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 +// +// https://www.apache.org/licenses/LICENSE-2.0 +// +// 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. + +// This file contains a few select absl::Hash tests that, due to their reliance +// on INSTANTIATE_TYPED_TEST_SUITE_P, require a large amount of memory to +// compile. Put new tests in hash_test.cc, not this file. + +#include "absl/hash/hash.h" + +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "gtest/gtest.h" +#include "absl/container/btree_map.h" +#include "absl/container/btree_set.h" +#include "absl/container/flat_hash_map.h" +#include "absl/container/flat_hash_set.h" +#include "absl/container/node_hash_map.h" +#include "absl/container/node_hash_set.h" +#include "absl/hash/hash_testing.h" +#include "absl/hash/internal/hash_test.h" + +namespace { + +using ::absl::hash_test_internal::is_hashable; +using ::absl::hash_test_internal::TypeErasedContainer; + +// Dummy type with unordered equality and hashing semantics. This preserves +// input order internally, and is used below to ensure we get test coverage +// for equal sequences with different iteraton orders. +template +class UnorderedSequence { + public: + UnorderedSequence() = default; + template + UnorderedSequence(std::initializer_list l) + : values_(l.begin(), l.end()) {} + template ::value, + bool>::type = true> + UnorderedSequence(ForwardIterator begin, ForwardIterator end) + : values_(begin, end) {} + // one-argument constructor of value type T, to appease older toolchains that + // get confused by one-element initializer lists in some contexts + explicit UnorderedSequence(const T& v) : values_(&v, &v + 1) {} + + using value_type = T; + + size_t size() const { return values_.size(); } + typename std::vector::const_iterator begin() const { + return values_.begin(); + } + typename std::vector::const_iterator end() const { return values_.end(); } + + friend bool operator==(const UnorderedSequence& lhs, + const UnorderedSequence& rhs) { + return lhs.size() == rhs.size() && + std::is_permutation(lhs.begin(), lhs.end(), rhs.begin()); + } + friend bool operator!=(const UnorderedSequence& lhs, + const UnorderedSequence& rhs) { + return !(lhs == rhs); + } + template + friend H AbslHashValue(H h, const UnorderedSequence& u) { + return H::combine(H::combine_unordered(std::move(h), u.begin(), u.end()), + u.size()); + } + + private: + std::vector values_; +}; + +template +class HashValueSequenceTest : public testing::Test {}; +TYPED_TEST_SUITE_P(HashValueSequenceTest); + +TYPED_TEST_P(HashValueSequenceTest, BasicUsage) { + EXPECT_TRUE((is_hashable::value)); + + using IntType = typename TypeParam::value_type; + auto a = static_cast(0); + auto b = static_cast(23); + auto c = static_cast(42); + + std::vector exemplars = { + TypeParam(), TypeParam(), TypeParam{a, b, c}, + TypeParam{a, c, b}, TypeParam{c, a, b}, TypeParam{a}, + TypeParam{a, a}, TypeParam{a, a, a}, TypeParam{a, a, b}, + TypeParam{a, b, a}, TypeParam{b, a, a}, TypeParam{a, b}, + TypeParam{b, c}}; + EXPECT_TRUE(absl::VerifyTypeImplementsAbslHashCorrectly(exemplars)); +} + +REGISTER_TYPED_TEST_SUITE_P(HashValueSequenceTest, BasicUsage); +using IntSequenceTypes = testing::Types< + std::deque, std::forward_list, std::list, std::vector, + std::vector, TypeErasedContainer>, std::set, + std::multiset, UnorderedSequence, + TypeErasedContainer>, std::unordered_set, + std::unordered_multiset, absl::flat_hash_set, + absl::node_hash_set, absl::btree_set>; +INSTANTIATE_TYPED_TEST_SUITE_P(My, HashValueSequenceTest, IntSequenceTypes); + +template +class HashValueNestedSequenceTest : public testing::Test {}; +TYPED_TEST_SUITE_P(HashValueNestedSequenceTest); + +TYPED_TEST_P(HashValueNestedSequenceTest, BasicUsage) { + using T = TypeParam; + using V = typename T::value_type; + std::vector exemplars = { + // empty case + T{}, + // sets of empty sets + T{V{}}, T{V{}, V{}}, T{V{}, V{}, V{}}, + // multisets of different values + T{V{1}}, T{V{1, 1}, V{1, 1}}, T{V{1, 1, 1}, V{1, 1, 1}, V{1, 1, 1}}, + // various orderings of same nested sets + T{V{}, V{1, 2}}, T{V{}, V{2, 1}}, T{V{1, 2}, V{}}, T{V{2, 1}, V{}}, + // various orderings of various nested sets, case 2 + T{V{1, 2}, V{3, 4}}, T{V{1, 2}, V{4, 3}}, T{V{1, 3}, V{2, 4}}, + T{V{1, 3}, V{4, 2}}, T{V{1, 4}, V{2, 3}}, T{V{1, 4}, V{3, 2}}, + T{V{2, 3}, V{1, 4}}, T{V{2, 3}, V{4, 1}}, T{V{2, 4}, V{1, 3}}, + T{V{2, 4}, V{3, 1}}, T{V{3, 4}, V{1, 2}}, T{V{3, 4}, V{2, 1}}}; + EXPECT_TRUE(absl::VerifyTypeImplementsAbslHashCorrectly(exemplars)); +} + +REGISTER_TYPED_TEST_SUITE_P(HashValueNestedSequenceTest, BasicUsage); +template +using TypeErasedSet = TypeErasedContainer>; + +using NestedIntSequenceTypes = testing::Types< + std::vector>, std::vector>, + std::vector>, UnorderedSequence>, + UnorderedSequence>, + UnorderedSequence>, TypeErasedSet>, + TypeErasedSet>, TypeErasedSet>>; +INSTANTIATE_TYPED_TEST_SUITE_P(My, HashValueNestedSequenceTest, + NestedIntSequenceTypes); + +template +class HashValueAssociativeMapTest : public testing::Test {}; +TYPED_TEST_SUITE_P(HashValueAssociativeMapTest); + +TYPED_TEST_P(HashValueAssociativeMapTest, BasicUsage) { + using M = TypeParam; + using V = typename M::value_type; + std::vector exemplars{M{}, + M{V{0, "foo"}}, + M{V{1, "foo"}}, + M{V{0, "bar"}}, + M{V{1, "bar"}}, + M{V{0, "foo"}, V{42, "bar"}}, + M{V{42, "bar"}, V{0, "foo"}}, + M{V{1, "foo"}, V{42, "bar"}}, + M{V{1, "foo"}, V{43, "bar"}}, + M{V{1, "foo"}, V{43, "baz"}}}; + EXPECT_TRUE(absl::VerifyTypeImplementsAbslHashCorrectly(exemplars)); +} + +REGISTER_TYPED_TEST_SUITE_P(HashValueAssociativeMapTest, BasicUsage); +using AssociativeMapTypes = testing::Types< + std::map, std::unordered_map, + absl::flat_hash_map, + absl::node_hash_map, absl::btree_map, + UnorderedSequence>>; +INSTANTIATE_TYPED_TEST_SUITE_P(My, HashValueAssociativeMapTest, + AssociativeMapTypes); + +template +class HashValueAssociativeMultimapTest : public testing::Test {}; +TYPED_TEST_SUITE_P(HashValueAssociativeMultimapTest); + +TYPED_TEST_P(HashValueAssociativeMultimapTest, BasicUsage) { + using MM = TypeParam; + using V = typename MM::value_type; + std::vector exemplars{MM{}, + MM{V{0, "foo"}}, + MM{V{1, "foo"}}, + MM{V{0, "bar"}}, + MM{V{1, "bar"}}, + MM{V{0, "foo"}, V{0, "bar"}}, + MM{V{0, "bar"}, V{0, "foo"}}, + MM{V{0, "foo"}, V{42, "bar"}}, + MM{V{1, "foo"}, V{42, "bar"}}, + MM{V{1, "foo"}, V{1, "foo"}, V{43, "bar"}}, + MM{V{1, "foo"}, V{43, "bar"}, V{1, "foo"}}, + MM{V{1, "foo"}, V{43, "baz"}}}; + EXPECT_TRUE(absl::VerifyTypeImplementsAbslHashCorrectly(exemplars)); +} + +REGISTER_TYPED_TEST_SUITE_P(HashValueAssociativeMultimapTest, BasicUsage); +using AssociativeMultimapTypes = + testing::Types, + std::unordered_multimap>; +INSTANTIATE_TYPED_TEST_SUITE_P(My, HashValueAssociativeMultimapTest, + AssociativeMultimapTypes); + +} // namespace diff --git a/absl/hash/hash_test.cc b/absl/hash/hash_test.cc index 6727dafa..a0e2e4a7 100644 --- a/absl/hash/hash_test.cc +++ b/absl/hash/hash_test.cc @@ -48,6 +48,7 @@ #include "absl/container/node_hash_map.h" #include "absl/container/node_hash_set.h" #include "absl/hash/hash_testing.h" +#include "absl/hash/internal/hash_test.h" #include "absl/hash/internal/spy_hash_state.h" #include "absl/meta/type_traits.h" #include "absl/numeric/int128.h" @@ -59,52 +60,9 @@ namespace { -// Utility wrapper of T for the purposes of testing the `AbslHash` type erasure -// mechanism. `TypeErasedValue` can be constructed with a `T`, and can -// be compared and hashed. However, all hashing goes through the hashing -// type-erasure framework. -template -class TypeErasedValue { - public: - TypeErasedValue() = default; - TypeErasedValue(const TypeErasedValue&) = default; - TypeErasedValue(TypeErasedValue&&) = default; - explicit TypeErasedValue(const T& n) : n_(n) {} - - template - friend H AbslHashValue(H hash_state, const TypeErasedValue& v) { - v.HashValue(absl::HashState::Create(&hash_state)); - return hash_state; - } - - void HashValue(absl::HashState state) const { - absl::HashState::combine(std::move(state), n_); - } - - bool operator==(const TypeErasedValue& rhs) const { return n_ == rhs.n_; } - bool operator!=(const TypeErasedValue& rhs) const { return !(*this == rhs); } - - private: - T n_; -}; - -// A TypeErasedValue refinement, for containers. It exposes the wrapped -// `value_type` and is constructible from an initializer list. -template -class TypeErasedContainer : public TypeErasedValue { - public: - using value_type = typename T::value_type; - TypeErasedContainer() = default; - TypeErasedContainer(const TypeErasedContainer&) = default; - TypeErasedContainer(TypeErasedContainer&&) = default; - explicit TypeErasedContainer(const T& n) : TypeErasedValue(n) {} - TypeErasedContainer(std::initializer_list init_list) - : TypeErasedContainer(T(init_list.begin(), init_list.end())) {} - // one-argument constructor of value type T, to appease older toolchains that - // get confused by one-element initializer lists in some contexts - explicit TypeErasedContainer(const value_type& v) - : TypeErasedContainer(T(&v, &v + 1)) {} -}; +using ::absl::hash_test_internal::is_hashable; +using ::absl::hash_test_internal::TypeErasedContainer; +using ::absl::hash_test_internal::TypeErasedValue; template using TypeErasedVector = TypeErasedContainer>; @@ -122,11 +80,6 @@ SpyHashState SpyHash(const T& value) { return SpyHashState::combine(SpyHashState(), value); } -// Helper trait to verify if T is hashable. We use absl::Hash's poison status to -// detect it. -template -using is_hashable = std::is_default_constructible>; - TYPED_TEST_P(HashValueIntTest, BasicUsage) { EXPECT_TRUE((is_hashable::value)); @@ -566,121 +519,6 @@ TEST(HashValueTest, StdBitset) { std::bitset(bit_strings[5].c_str())})); } // namespace -// Dummy type with unordered equality and hashing semantics. This preserves -// input order internally, and is used below to ensure we get test coverage -// for equal sequences with different iteraton orders. -template -class UnorderedSequence { - public: - UnorderedSequence() = default; - template - UnorderedSequence(std::initializer_list l) - : values_(l.begin(), l.end()) {} - template ::value, - bool>::type = true> - UnorderedSequence(ForwardIterator begin, ForwardIterator end) - : values_(begin, end) {} - // one-argument constructor of value type T, to appease older toolchains that - // get confused by one-element initializer lists in some contexts - explicit UnorderedSequence(const T& v) : values_(&v, &v + 1) {} - - using value_type = T; - - size_t size() const { return values_.size(); } - typename std::vector::const_iterator begin() const { - return values_.begin(); - } - typename std::vector::const_iterator end() const { return values_.end(); } - - friend bool operator==(const UnorderedSequence& lhs, - const UnorderedSequence& rhs) { - return lhs.size() == rhs.size() && - std::is_permutation(lhs.begin(), lhs.end(), rhs.begin()); - } - friend bool operator!=(const UnorderedSequence& lhs, - const UnorderedSequence& rhs) { - return !(lhs == rhs); - } - template - friend H AbslHashValue(H h, const UnorderedSequence& u) { - return H::combine(H::combine_unordered(std::move(h), u.begin(), u.end()), - u.size()); - } - - private: - std::vector values_; -}; - -template -class HashValueSequenceTest : public testing::Test { -}; -TYPED_TEST_SUITE_P(HashValueSequenceTest); - -TYPED_TEST_P(HashValueSequenceTest, BasicUsage) { - EXPECT_TRUE((is_hashable::value)); - - using IntType = typename TypeParam::value_type; - auto a = static_cast(0); - auto b = static_cast(23); - auto c = static_cast(42); - - std::vector exemplars = { - TypeParam(), TypeParam(), TypeParam{a, b, c}, - TypeParam{a, c, b}, TypeParam{c, a, b}, TypeParam{a}, - TypeParam{a, a}, TypeParam{a, a, a}, TypeParam{a, a, b}, - TypeParam{a, b, a}, TypeParam{b, a, a}, TypeParam{a, b}, - TypeParam{b, c}}; - EXPECT_TRUE(absl::VerifyTypeImplementsAbslHashCorrectly(exemplars)); -} - -REGISTER_TYPED_TEST_SUITE_P(HashValueSequenceTest, BasicUsage); -using IntSequenceTypes = testing::Types< - std::deque, std::forward_list, std::list, std::vector, - std::vector, TypeErasedContainer>, std::set, - std::multiset, UnorderedSequence, - TypeErasedContainer>, std::unordered_set, - std::unordered_multiset, absl::flat_hash_set, - absl::node_hash_set, absl::btree_set>; -INSTANTIATE_TYPED_TEST_SUITE_P(My, HashValueSequenceTest, IntSequenceTypes); - -template -class HashValueNestedSequenceTest : public testing::Test {}; -TYPED_TEST_SUITE_P(HashValueNestedSequenceTest); - -TYPED_TEST_P(HashValueNestedSequenceTest, BasicUsage) { - using T = TypeParam; - using V = typename T::value_type; - std::vector exemplars = { - // empty case - T{}, - // sets of empty sets - T{V{}}, T{V{}, V{}}, T{V{}, V{}, V{}}, - // multisets of different values - T{V{1}}, T{V{1, 1}, V{1, 1}}, T{V{1, 1, 1}, V{1, 1, 1}, V{1, 1, 1}}, - // various orderings of same nested sets - T{V{}, V{1, 2}}, T{V{}, V{2, 1}}, T{V{1, 2}, V{}}, T{V{2, 1}, V{}}, - // various orderings of various nested sets, case 2 - T{V{1, 2}, V{3, 4}}, T{V{1, 2}, V{4, 3}}, T{V{1, 3}, V{2, 4}}, - T{V{1, 3}, V{4, 2}}, T{V{1, 4}, V{2, 3}}, T{V{1, 4}, V{3, 2}}, - T{V{2, 3}, V{1, 4}}, T{V{2, 3}, V{4, 1}}, T{V{2, 4}, V{1, 3}}, - T{V{2, 4}, V{3, 1}}, T{V{3, 4}, V{1, 2}}, T{V{3, 4}, V{2, 1}}}; - EXPECT_TRUE(absl::VerifyTypeImplementsAbslHashCorrectly(exemplars)); -} - -REGISTER_TYPED_TEST_SUITE_P(HashValueNestedSequenceTest, BasicUsage); -template -using TypeErasedSet = TypeErasedContainer>; - -using NestedIntSequenceTypes = testing::Types< - std::vector>, std::vector>, - std::vector>, UnorderedSequence>, - UnorderedSequence>, - UnorderedSequence>, TypeErasedSet>, - TypeErasedSet>, TypeErasedSet>>; -INSTANTIATE_TYPED_TEST_SUITE_P(My, HashValueNestedSequenceTest, - NestedIntSequenceTypes); - // Private type that only supports AbslHashValue to make sure our chosen hash // implementation is recursive within absl::Hash. // It uses std::abs() on the value to provide different bitwise representations @@ -839,64 +677,6 @@ TEST(HashValueTest, Variant) { #endif } -template -class HashValueAssociativeMapTest : public testing::Test {}; -TYPED_TEST_SUITE_P(HashValueAssociativeMapTest); - -TYPED_TEST_P(HashValueAssociativeMapTest, BasicUsage) { - using M = TypeParam; - using V = typename M::value_type; - std::vector exemplars{M{}, - M{V{0, "foo"}}, - M{V{1, "foo"}}, - M{V{0, "bar"}}, - M{V{1, "bar"}}, - M{V{0, "foo"}, V{42, "bar"}}, - M{V{42, "bar"}, V{0, "foo"}}, - M{V{1, "foo"}, V{42, "bar"}}, - M{V{1, "foo"}, V{43, "bar"}}, - M{V{1, "foo"}, V{43, "baz"}}}; - EXPECT_TRUE(absl::VerifyTypeImplementsAbslHashCorrectly(exemplars)); -} - -REGISTER_TYPED_TEST_SUITE_P(HashValueAssociativeMapTest, BasicUsage); -using AssociativeMapTypes = testing::Types< - std::map, std::unordered_map, - absl::flat_hash_map, - absl::node_hash_map, absl::btree_map, - UnorderedSequence>>; -INSTANTIATE_TYPED_TEST_SUITE_P(My, HashValueAssociativeMapTest, - AssociativeMapTypes); - -template -class HashValueAssociativeMultimapTest : public testing::Test {}; -TYPED_TEST_SUITE_P(HashValueAssociativeMultimapTest); - -TYPED_TEST_P(HashValueAssociativeMultimapTest, BasicUsage) { - using MM = TypeParam; - using V = typename MM::value_type; - std::vector exemplars{MM{}, - MM{V{0, "foo"}}, - MM{V{1, "foo"}}, - MM{V{0, "bar"}}, - MM{V{1, "bar"}}, - MM{V{0, "foo"}, V{0, "bar"}}, - MM{V{0, "bar"}, V{0, "foo"}}, - MM{V{0, "foo"}, V{42, "bar"}}, - MM{V{1, "foo"}, V{42, "bar"}}, - MM{V{1, "foo"}, V{1, "foo"}, V{43, "bar"}}, - MM{V{1, "foo"}, V{43, "bar"}, V{1, "foo"}}, - MM{V{1, "foo"}, V{43, "baz"}}}; - EXPECT_TRUE(absl::VerifyTypeImplementsAbslHashCorrectly(exemplars)); -} - -REGISTER_TYPED_TEST_SUITE_P(HashValueAssociativeMultimapTest, BasicUsage); -using AssociativeMultimapTypes = - testing::Types, - std::unordered_multimap>; -INSTANTIATE_TYPED_TEST_SUITE_P(My, HashValueAssociativeMultimapTest, - AssociativeMultimapTypes); - TEST(HashValueTest, ReferenceWrapper) { EXPECT_TRUE(is_hashable>::value); diff --git a/absl/hash/internal/hash_test.h b/absl/hash/internal/hash_test.h new file mode 100644 index 00000000..9963dc0b --- /dev/null +++ b/absl/hash/internal/hash_test.h @@ -0,0 +1,87 @@ +// Copyright 2023 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 +// +// https://www.apache.org/licenses/LICENSE-2.0 +// +// 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. + +// Common code shared between absl/hash/hash_test.cc and +// absl/hash/hash_instantiated_test.cc. + +#ifndef ABSL_HASH_INTERNAL_HASH_TEST_H_ +#define ABSL_HASH_INTERNAL_HASH_TEST_H_ + +#include +#include + +#include "absl/base/config.h" +#include "absl/hash/hash.h" + +namespace absl { +ABSL_NAMESPACE_BEGIN +namespace hash_test_internal { + +// Utility wrapper of T for the purposes of testing the `AbslHash` type erasure +// mechanism. `TypeErasedValue` can be constructed with a `T`, and can +// be compared and hashed. However, all hashing goes through the hashing +// type-erasure framework. +template +class TypeErasedValue { + public: + TypeErasedValue() = default; + TypeErasedValue(const TypeErasedValue&) = default; + TypeErasedValue(TypeErasedValue&&) = default; + explicit TypeErasedValue(const T& n) : n_(n) {} + + template + friend H AbslHashValue(H hash_state, const TypeErasedValue& v) { + v.HashValue(absl::HashState::Create(&hash_state)); + return hash_state; + } + + void HashValue(absl::HashState state) const { + absl::HashState::combine(std::move(state), n_); + } + + bool operator==(const TypeErasedValue& rhs) const { return n_ == rhs.n_; } + bool operator!=(const TypeErasedValue& rhs) const { return !(*this == rhs); } + + private: + T n_; +}; + +// A TypeErasedValue refinement, for containers. It exposes the wrapped +// `value_type` and is constructible from an initializer list. +template +class TypeErasedContainer : public TypeErasedValue { + public: + using value_type = typename T::value_type; + TypeErasedContainer() = default; + TypeErasedContainer(const TypeErasedContainer&) = default; + TypeErasedContainer(TypeErasedContainer&&) = default; + explicit TypeErasedContainer(const T& n) : TypeErasedValue(n) {} + TypeErasedContainer(std::initializer_list init_list) + : TypeErasedContainer(T(init_list.begin(), init_list.end())) {} + // one-argument constructor of value type T, to appease older toolchains that + // get confused by one-element initializer lists in some contexts + explicit TypeErasedContainer(const value_type& v) + : TypeErasedContainer(T(&v, &v + 1)) {} +}; + +// Helper trait to verify if T is hashable. We use absl::Hash's poison status to +// detect it. +template +using is_hashable = std::is_default_constructible>; + +} // namespace hash_test_internal +ABSL_NAMESPACE_END +} // namespace absl + +#endif // ABSL_HASH_INTERNAL_HASH_TEST_H_ -- cgit v1.2.3