02aadae109
This was introduced in 2011 in r74904 (and used in several followup changes) to support the implementation of base::Bind. In 2014, base::Bind was rebuilt with a variadic template in r314847, removing most uses. In 2016, the last usage was removed in r402716. This was used to enforce the now-gone rule in the style guide of not using non-const references. Given that there's been no use in the past six years, it's time to clean it out. Bug: none Change-Id: I8176d5466e14001f1ceb61fee24214b273c3f0ae Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3625509 Commit-Queue: Avi Drissman <avi@chromium.org> Reviewed-by: danakj <danakj@chromium.org> Cr-Commit-Position: refs/heads/main@{#999216}
127 lines
5.5 KiB
C++
127 lines
5.5 KiB
C++
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#include "base/template_util.h"
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#include <string>
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#include <type_traits>
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#include "base/containers/flat_tree.h"
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#include "base/test/move_only_int.h"
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#include "testing/gtest/include/gtest/gtest.h"
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namespace base {
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namespace {
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enum SimpleEnum { SIMPLE_ENUM };
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enum EnumWithExplicitType : uint64_t { ENUM_WITH_EXPLICIT_TYPE };
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enum class ScopedEnum { SCOPED_ENUM };
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enum class ScopedEnumWithOperator { SCOPED_ENUM_WITH_OPERATOR };
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std::ostream& operator<<(std::ostream& os, ScopedEnumWithOperator v) {
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return os;
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}
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struct SimpleStruct {};
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struct StructWithOperator {};
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std::ostream& operator<<(std::ostream& os, const StructWithOperator& v) {
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return os;
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}
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struct StructWithToString {
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std::string ToString() const { return ""; }
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};
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// A few standard types that definitely support printing.
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static_assert(internal::SupportsOstreamOperator<int>::value,
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"ints should be printable");
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static_assert(internal::SupportsOstreamOperator<const char*>::value,
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"C strings should be printable");
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static_assert(internal::SupportsOstreamOperator<std::string>::value,
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"std::string should be printable");
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// Various kinds of enums operator<< support.
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static_assert(internal::SupportsOstreamOperator<SimpleEnum>::value,
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"simple enum should be printable by value");
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static_assert(internal::SupportsOstreamOperator<const SimpleEnum&>::value,
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"simple enum should be printable by const ref");
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static_assert(internal::SupportsOstreamOperator<EnumWithExplicitType>::value,
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"enum with explicit type should be printable by value");
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static_assert(
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internal::SupportsOstreamOperator<const EnumWithExplicitType&>::value,
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"enum with explicit type should be printable by const ref");
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static_assert(!internal::SupportsOstreamOperator<ScopedEnum>::value,
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"scoped enum should not be printable by value");
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static_assert(!internal::SupportsOstreamOperator<const ScopedEnum&>::value,
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"simple enum should not be printable by const ref");
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static_assert(internal::SupportsOstreamOperator<ScopedEnumWithOperator>::value,
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"scoped enum with operator<< should be printable by value");
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static_assert(
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internal::SupportsOstreamOperator<const ScopedEnumWithOperator&>::value,
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"scoped enum with operator<< should be printable by const ref");
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// operator<< support on structs.
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static_assert(!internal::SupportsOstreamOperator<SimpleStruct>::value,
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"simple struct should not be printable by value");
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static_assert(!internal::SupportsOstreamOperator<const SimpleStruct&>::value,
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"simple struct should not be printable by const ref");
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static_assert(internal::SupportsOstreamOperator<StructWithOperator>::value,
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"struct with operator<< should be printable by value");
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static_assert(
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internal::SupportsOstreamOperator<const StructWithOperator&>::value,
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"struct with operator<< should be printable by const ref");
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// .ToString() support on structs.
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static_assert(!internal::SupportsToString<SimpleStruct>::value,
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"simple struct value doesn't support .ToString()");
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static_assert(!internal::SupportsToString<const SimpleStruct&>::value,
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"simple struct const ref doesn't support .ToString()");
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static_assert(internal::SupportsToString<StructWithToString>::value,
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"struct with .ToString() should be printable by value");
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static_assert(internal::SupportsToString<const StructWithToString&>::value,
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"struct with .ToString() should be printable by const ref");
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// is_scoped_enum
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TEST(TemplateUtil, IsScopedEnum) {
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static_assert(!is_scoped_enum<int>::value, "");
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static_assert(!is_scoped_enum<SimpleEnum>::value, "");
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static_assert(!is_scoped_enum<EnumWithExplicitType>::value, "");
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static_assert(is_scoped_enum<ScopedEnum>::value, "");
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}
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TEST(TemplateUtil, RemoveCvRefT) {
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static_assert(std::is_same<int, remove_cvref_t<const int>>::value, "");
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static_assert(std::is_same<int, remove_cvref_t<const volatile int>>::value,
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"");
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static_assert(std::is_same<int, remove_cvref_t<int&>>::value, "");
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static_assert(std::is_same<int, remove_cvref_t<const int&>>::value, "");
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static_assert(std::is_same<int, remove_cvref_t<const volatile int&>>::value,
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"");
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static_assert(std::is_same<int, remove_cvref_t<int&&>>::value, "");
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static_assert(
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std::is_same<SimpleStruct, remove_cvref_t<const SimpleStruct&>>::value,
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"");
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static_assert(std::is_same<int*, remove_cvref_t<int*>>::value, "");
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// Test references and pointers to arrays.
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static_assert(std::is_same<int[3], remove_cvref_t<int[3]>>::value, "");
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static_assert(std::is_same<int[3], remove_cvref_t<int(&)[3]>>::value, "");
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static_assert(std::is_same<int(*)[3], remove_cvref_t<int(*)[3]>>::value, "");
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// Test references and pointers to functions.
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static_assert(std::is_same<void(int), remove_cvref_t<void(int)>>::value, "");
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static_assert(std::is_same<void(int), remove_cvref_t<void (&)(int)>>::value,
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"");
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static_assert(
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std::is_same<void (*)(int), remove_cvref_t<void (*)(int)>>::value, "");
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}
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TEST(TemplateUtil, IsConstantEvaluated) {
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// base::is_constant_evaluated() should return whether it is evaluated as part
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// of a constant expression.
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static_assert(is_constant_evaluated(), "");
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EXPECT_FALSE(is_constant_evaluated());
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}
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} // namespace
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} // namespace base
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