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// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/template_util.h"
#include <string>
#include <type_traits>
#include "base/containers/flat_tree.h"
#include "base/test/move_only_int.h"
#include "testing/gtest/include/gtest/gtest.h"
namespace base {
namespace {
enum SimpleEnum { SIMPLE_ENUM };
enum EnumWithExplicitType : uint64_t { ENUM_WITH_EXPLICIT_TYPE };
enum class ScopedEnum { SCOPED_ENUM };
enum class ScopedEnumWithOperator { SCOPED_ENUM_WITH_OPERATOR };
std::ostream& operator<<(std::ostream& os, ScopedEnumWithOperator v) {
return os;
}
struct SimpleStruct {};
struct StructWithOperator {};
std::ostream& operator<<(std::ostream& os, const StructWithOperator& v) {
return os;
}
struct StructWithToString {
std::string ToString() const { return ""; }
};
// A few standard types that definitely support printing.
static_assert(internal::SupportsOstreamOperator<int>::value,
"ints should be printable");
static_assert(internal::SupportsOstreamOperator<const char*>::value,
"C strings should be printable");
static_assert(internal::SupportsOstreamOperator<std::string>::value,
"std::string should be printable");
// Various kinds of enums operator<< support.
static_assert(internal::SupportsOstreamOperator<SimpleEnum>::value,
"simple enum should be printable by value");
static_assert(internal::SupportsOstreamOperator<const SimpleEnum&>::value,
"simple enum should be printable by const ref");
static_assert(internal::SupportsOstreamOperator<EnumWithExplicitType>::value,
"enum with explicit type should be printable by value");
static_assert(
internal::SupportsOstreamOperator<const EnumWithExplicitType&>::value,
"enum with explicit type should be printable by const ref");
static_assert(!internal::SupportsOstreamOperator<ScopedEnum>::value,
"scoped enum should not be printable by value");
static_assert(!internal::SupportsOstreamOperator<const ScopedEnum&>::value,
"simple enum should not be printable by const ref");
static_assert(internal::SupportsOstreamOperator<ScopedEnumWithOperator>::value,
"scoped enum with operator<< should be printable by value");
static_assert(
internal::SupportsOstreamOperator<const ScopedEnumWithOperator&>::value,
"scoped enum with operator<< should be printable by const ref");
// operator<< support on structs.
static_assert(!internal::SupportsOstreamOperator<SimpleStruct>::value,
"simple struct should not be printable by value");
static_assert(!internal::SupportsOstreamOperator<const SimpleStruct&>::value,
"simple struct should not be printable by const ref");
static_assert(internal::SupportsOstreamOperator<StructWithOperator>::value,
"struct with operator<< should be printable by value");
static_assert(
internal::SupportsOstreamOperator<const StructWithOperator&>::value,
"struct with operator<< should be printable by const ref");
// .ToString() support on structs.
static_assert(!internal::SupportsToString<SimpleStruct>::value,
"simple struct value doesn't support .ToString()");
static_assert(!internal::SupportsToString<const SimpleStruct&>::value,
"simple struct const ref doesn't support .ToString()");
static_assert(internal::SupportsToString<StructWithToString>::value,
"struct with .ToString() should be printable by value");
static_assert(internal::SupportsToString<const StructWithToString&>::value,
"struct with .ToString() should be printable by const ref");
// is_scoped_enum
TEST(TemplateUtil, IsScopedEnum) {
static_assert(!is_scoped_enum<int>::value, "");
static_assert(!is_scoped_enum<SimpleEnum>::value, "");
static_assert(!is_scoped_enum<EnumWithExplicitType>::value, "");
static_assert(is_scoped_enum<ScopedEnum>::value, "");
}
TEST(TemplateUtil, RemoveCvRefT) {
static_assert(std::is_same<int, remove_cvref_t<const int>>::value, "");
static_assert(std::is_same<int, remove_cvref_t<const volatile int>>::value,
"");
static_assert(std::is_same<int, remove_cvref_t<int&>>::value, "");
static_assert(std::is_same<int, remove_cvref_t<const int&>>::value, "");
static_assert(std::is_same<int, remove_cvref_t<const volatile int&>>::value,
"");
static_assert(std::is_same<int, remove_cvref_t<int&&>>::value, "");
static_assert(
std::is_same<SimpleStruct, remove_cvref_t<const SimpleStruct&>>::value,
"");
static_assert(std::is_same<int*, remove_cvref_t<int*>>::value, "");
// Test references and pointers to arrays.
static_assert(std::is_same<int[3], remove_cvref_t<int[3]>>::value, "");
static_assert(std::is_same<int[3], remove_cvref_t<int(&)[3]>>::value, "");
static_assert(std::is_same<int(*)[3], remove_cvref_t<int(*)[3]>>::value, "");
// Test references and pointers to functions.
static_assert(std::is_same<void(int), remove_cvref_t<void(int)>>::value, "");
static_assert(std::is_same<void(int), remove_cvref_t<void (&)(int)>>::value,
"");
static_assert(
std::is_same<void (*)(int), remove_cvref_t<void (*)(int)>>::value, "");
}
} // namespace
} // namespace base
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