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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef TEST_SUPPORT_PROPAGATE_VALUE_CATEGORY
#define TEST_SUPPORT_PROPAGATE_VALUE_CATEGORY
#include "test_macros.h"
#include <type_traits>
#if TEST_STD_VER < 11
#error this header may only be used in C++11
#endif
using UnderlyingVCType = unsigned;
enum ValueCategory : UnderlyingVCType {
VC_None = 0,
VC_LVal = 1 << 0,
VC_RVal = 1 << 1,
VC_Const = 1 << 2,
VC_Volatile = 1 << 3,
VC_ConstVolatile = VC_Const | VC_Volatile
};
inline constexpr ValueCategory operator&(ValueCategory LHS, ValueCategory RHS) {
return ValueCategory(LHS & (UnderlyingVCType)RHS);
}
inline constexpr ValueCategory operator|(ValueCategory LHS, ValueCategory RHS) {
return ValueCategory(LHS | (UnderlyingVCType)RHS);
}
inline constexpr ValueCategory operator^(ValueCategory LHS, ValueCategory RHS) {
return ValueCategory(LHS ^ (UnderlyingVCType)RHS);
}
inline constexpr bool isValidValueCategory(ValueCategory VC) {
return (VC & (VC_LVal | VC_RVal)) != (VC_LVal | VC_RVal);
}
inline constexpr bool hasValueCategory(ValueCategory Arg, ValueCategory Key) {
return Arg == Key || ((Arg & Key) == Key);
}
template <class Tp>
using UnCVRef =
typename std::remove_cv<typename std::remove_reference<Tp>::type>::type;
template <class Tp>
constexpr ValueCategory getReferenceQuals() {
return std::is_lvalue_reference<Tp>::value
? VC_LVal
: (std::is_rvalue_reference<Tp>::value ? VC_RVal : VC_None);
}
static_assert(getReferenceQuals<int>() == VC_None, "");
static_assert(getReferenceQuals<int &>() == VC_LVal, "");
static_assert(getReferenceQuals<int &&>() == VC_RVal, "");
template <class Tp>
constexpr ValueCategory getCVQuals() {
using Vp = typename std::remove_reference<Tp>::type;
return std::is_const<Vp>::value && std::is_volatile<Vp>::value
? VC_ConstVolatile
: (std::is_const<Vp>::value
? VC_Const
: (std::is_volatile<Vp>::value ? VC_Volatile : VC_None));
}
static_assert(getCVQuals<int>() == VC_None, "");
static_assert(getCVQuals<int const>() == VC_Const, "");
static_assert(getCVQuals<int volatile>() == VC_Volatile, "");
static_assert(getCVQuals<int const volatile>() == VC_ConstVolatile, "");
static_assert(getCVQuals<int &>() == VC_None, "");
static_assert(getCVQuals<int const &>() == VC_Const, "");
template <class Tp>
inline constexpr ValueCategory getValueCategory() {
return getReferenceQuals<Tp>() | getCVQuals<Tp>();
}
static_assert(getValueCategory<int>() == VC_None, "");
static_assert(getValueCategory<int const &>() == (VC_LVal | VC_Const), "");
static_assert(getValueCategory<int const volatile &&>() ==
(VC_RVal | VC_ConstVolatile),
"");
template <ValueCategory VC>
struct ApplyValueCategory {
private:
static_assert(isValidValueCategory(VC), "");
template <bool Pred, class Then, class Else>
using CondT = typename std::conditional<Pred, Then, Else>::type;
public:
template <class Tp, class Vp = UnCVRef<Tp>>
using ApplyCVQuals = CondT<
hasValueCategory(VC, VC_ConstVolatile), typename std::add_cv<Vp>::type,
CondT<hasValueCategory(VC, VC_Const), typename std::add_const<Vp>::type,
CondT<hasValueCategory(VC, VC_Volatile),
typename std::add_volatile<Vp>::type, Tp>>>;
template <class Tp, class Vp = typename std::remove_reference<Tp>::type>
using ApplyReferenceQuals =
CondT<hasValueCategory(VC, VC_LVal),
typename std::add_lvalue_reference<Vp>::type,
CondT<hasValueCategory(VC, VC_RVal),
typename std::add_rvalue_reference<Vp>::type, Vp>>;
template <class Tp>
using Apply = ApplyReferenceQuals<ApplyCVQuals<UnCVRef<Tp>>>;
template <class Tp, bool Dummy = true,
typename std::enable_if<Dummy && (VC & VC_LVal), bool>::type = true>
static Apply<UnCVRef<Tp>> cast(Tp &&t) {
using ToType = Apply<UnCVRef<Tp>>;
return static_cast<ToType>(t);
}
template <class Tp, bool Dummy = true,
typename std::enable_if<Dummy && (VC & VC_RVal), bool>::type = true>
static Apply<UnCVRef<Tp>> cast(Tp &&t) {
using ToType = Apply<UnCVRef<Tp>>;
return static_cast<ToType>(std::move(t));
}
template <
class Tp, bool Dummy = true,
typename std::enable_if<Dummy && ((VC & (VC_LVal | VC_RVal)) == VC_None),
bool>::type = true>
static Apply<UnCVRef<Tp>> cast(Tp &&t) {
return t;
}
};
template <ValueCategory VC, class Tp>
using ApplyValueCategoryT = typename ApplyValueCategory<VC>::template Apply<Tp>;
template <class Tp>
using PropagateValueCategory = ApplyValueCategory<getValueCategory<Tp>()>;
template <class Tp, class Up>
using PropagateValueCategoryT =
typename ApplyValueCategory<getValueCategory<Tp>()>::template Apply<Up>;
template <ValueCategory VC, class Tp>
typename ApplyValueCategory<VC>::template Apply<Tp> ValueCategoryCast(Tp &&t) {
return ApplyValueCategory<VC>::cast(std::forward<Tp>(t));
};
#endif // TEST_SUPPORT_PROPAGATE_VALUE_CATEGORY
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