229 lines
6.8 KiB
C++
229 lines
6.8 KiB
C++
// Tencent is pleased to support the open source community by making RapidJSON available.
|
|
//
|
|
// Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. All rights reserved.
|
|
//
|
|
// Licensed under the MIT License (the "License"); you may not use this file except
|
|
// in compliance with the License. You may obtain a copy of the License at
|
|
//
|
|
// http://opensource.org/licenses/MIT
|
|
//
|
|
// 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.
|
|
|
|
#ifndef RAPIDJSON_INTERNAL_META_H_
|
|
#define RAPIDJSON_INTERNAL_META_H_
|
|
|
|
#include "../rapidjson.h"
|
|
|
|
#ifdef __GNUC__
|
|
RAPIDJSON_DIAG_PUSH
|
|
RAPIDJSON_DIAG_OFF(effc++)
|
|
#endif
|
|
#if defined(_MSC_VER)
|
|
RAPIDJSON_DIAG_PUSH
|
|
RAPIDJSON_DIAG_OFF(6334)
|
|
#endif
|
|
|
|
#if RAPIDJSON_HAS_CXX11_TYPETRAITS
|
|
#include <type_traits>
|
|
#endif
|
|
|
|
//@cond RAPIDJSON_INTERNAL
|
|
RAPIDJSON_NAMESPACE_BEGIN
|
|
namespace internal {
|
|
|
|
// Helper to wrap/convert arbitrary types to void, useful for arbitrary type matching
|
|
template <typename T>
|
|
struct Void {
|
|
typedef void Type;
|
|
};
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
// BoolType, TrueType, FalseType
|
|
//
|
|
template <bool Cond>
|
|
struct BoolType {
|
|
static const bool Value = Cond;
|
|
typedef BoolType Type;
|
|
};
|
|
typedef BoolType<true> TrueType;
|
|
typedef BoolType<false> FalseType;
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
// SelectIf, BoolExpr, NotExpr, AndExpr, OrExpr
|
|
//
|
|
|
|
template <bool C>
|
|
struct SelectIfImpl {
|
|
template <typename T1, typename T2>
|
|
struct Apply {
|
|
typedef T1 Type;
|
|
};
|
|
};
|
|
template <>
|
|
struct SelectIfImpl<false> {
|
|
template <typename T1, typename T2>
|
|
struct Apply {
|
|
typedef T2 Type;
|
|
};
|
|
};
|
|
template <bool C, typename T1, typename T2>
|
|
struct SelectIfCond : SelectIfImpl<C>::template Apply<T1, T2> {};
|
|
template <typename C, typename T1, typename T2>
|
|
struct SelectIf : SelectIfCond<C::Value, T1, T2> {};
|
|
|
|
template <bool Cond1, bool Cond2>
|
|
struct AndExprCond : FalseType {};
|
|
template <>
|
|
struct AndExprCond<true, true> : TrueType {};
|
|
template <bool Cond1, bool Cond2>
|
|
struct OrExprCond : TrueType {};
|
|
template <>
|
|
struct OrExprCond<false, false> : FalseType {};
|
|
|
|
template <typename C>
|
|
struct BoolExpr : SelectIf<C, TrueType, FalseType>::Type {};
|
|
template <typename C>
|
|
struct NotExpr : SelectIf<C, FalseType, TrueType>::Type {};
|
|
template <typename C1, typename C2>
|
|
struct AndExpr : AndExprCond<C1::Value, C2::Value>::Type {};
|
|
template <typename C1, typename C2>
|
|
struct OrExpr : OrExprCond<C1::Value, C2::Value>::Type {};
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
// AddConst, MaybeAddConst, RemoveConst
|
|
template <typename T>
|
|
struct AddConst {
|
|
typedef const T Type;
|
|
};
|
|
template <bool Constify, typename T>
|
|
struct MaybeAddConst : SelectIfCond<Constify, const T, T> {};
|
|
template <typename T>
|
|
struct RemoveConst {
|
|
typedef T Type;
|
|
};
|
|
template <typename T>
|
|
struct RemoveConst<const T> {
|
|
typedef T Type;
|
|
};
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
// IsSame, IsConst, IsMoreConst, IsPointer
|
|
//
|
|
template <typename T, typename U>
|
|
struct IsSame : FalseType {};
|
|
template <typename T>
|
|
struct IsSame<T, T> : TrueType {};
|
|
|
|
template <typename T>
|
|
struct IsConst : FalseType {};
|
|
template <typename T>
|
|
struct IsConst<const T> : TrueType {};
|
|
|
|
template <typename CT, typename T>
|
|
struct IsMoreConst : AndExpr<IsSame<typename RemoveConst<CT>::Type, typename RemoveConst<T>::Type>,
|
|
BoolType<IsConst<CT>::Value >= IsConst<T>::Value>>::Type {};
|
|
|
|
template <typename T>
|
|
struct IsPointer : FalseType {};
|
|
template <typename T>
|
|
struct IsPointer<T*> : TrueType {};
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
// IsBaseOf
|
|
//
|
|
#if RAPIDJSON_HAS_CXX11_TYPETRAITS
|
|
|
|
template <typename B, typename D>
|
|
struct IsBaseOf : BoolType<::std::is_base_of<B, D>::value> {};
|
|
|
|
#else // simplified version adopted from Boost
|
|
|
|
template <typename B, typename D>
|
|
struct IsBaseOfImpl {
|
|
RAPIDJSON_STATIC_ASSERT(sizeof(B) != 0);
|
|
RAPIDJSON_STATIC_ASSERT(sizeof(D) != 0);
|
|
|
|
typedef char (&Yes)[1];
|
|
typedef char (&No)[2];
|
|
|
|
template <typename T>
|
|
static Yes Check(const D*, T);
|
|
static No Check(const B*, int);
|
|
|
|
struct Host {
|
|
operator const B*() const;
|
|
operator const D*();
|
|
};
|
|
|
|
enum { Value = (sizeof(Check(Host(), 0)) == sizeof(Yes)) };
|
|
};
|
|
|
|
template <typename B, typename D>
|
|
struct IsBaseOf : OrExpr<IsSame<B, D>, BoolExpr<IsBaseOfImpl<B, D>>>::Type {};
|
|
|
|
#endif // RAPIDJSON_HAS_CXX11_TYPETRAITS
|
|
|
|
//////////////////////////////////////////////////////////////////////////
|
|
// EnableIf / DisableIf
|
|
//
|
|
template <bool Condition, typename T = void>
|
|
struct EnableIfCond {
|
|
typedef T Type;
|
|
};
|
|
template <typename T>
|
|
struct EnableIfCond<false, T> { /* empty */
|
|
};
|
|
|
|
template <bool Condition, typename T = void>
|
|
struct DisableIfCond {
|
|
typedef T Type;
|
|
};
|
|
template <typename T>
|
|
struct DisableIfCond<true, T> { /* empty */
|
|
};
|
|
|
|
template <typename Condition, typename T = void>
|
|
struct EnableIf : EnableIfCond<Condition::Value, T> {};
|
|
|
|
template <typename Condition, typename T = void>
|
|
struct DisableIf : DisableIfCond<Condition::Value, T> {};
|
|
|
|
// SFINAE helpers
|
|
struct SfinaeTag {};
|
|
template <typename T>
|
|
struct RemoveSfinaeTag;
|
|
template <typename T>
|
|
struct RemoveSfinaeTag<SfinaeTag& (*)(T)> {
|
|
typedef T Type;
|
|
};
|
|
|
|
#define RAPIDJSON_REMOVEFPTR_(type) \
|
|
typename ::RAPIDJSON_NAMESPACE::internal::RemoveSfinaeTag<::RAPIDJSON_NAMESPACE::internal::SfinaeTag&(*)type>::Type
|
|
|
|
#define RAPIDJSON_ENABLEIF(cond) \
|
|
typename ::RAPIDJSON_NAMESPACE::internal::EnableIf<RAPIDJSON_REMOVEFPTR_(cond)>::Type* = NULL
|
|
|
|
#define RAPIDJSON_DISABLEIF(cond) \
|
|
typename ::RAPIDJSON_NAMESPACE::internal::DisableIf<RAPIDJSON_REMOVEFPTR_(cond)>::Type* = NULL
|
|
|
|
#define RAPIDJSON_ENABLEIF_RETURN(cond, returntype) \
|
|
typename ::RAPIDJSON_NAMESPACE::internal::EnableIf<RAPIDJSON_REMOVEFPTR_(cond), \
|
|
RAPIDJSON_REMOVEFPTR_(returntype)>::Type
|
|
|
|
#define RAPIDJSON_DISABLEIF_RETURN(cond, returntype) \
|
|
typename ::RAPIDJSON_NAMESPACE::internal::DisableIf<RAPIDJSON_REMOVEFPTR_(cond), \
|
|
RAPIDJSON_REMOVEFPTR_(returntype)>::Type
|
|
|
|
} // namespace internal
|
|
RAPIDJSON_NAMESPACE_END
|
|
//@endcond
|
|
|
|
#if defined(__GNUC__) || defined(_MSC_VER)
|
|
RAPIDJSON_DIAG_POP
|
|
#endif
|
|
|
|
#endif // RAPIDJSON_INTERNAL_META_H_
|