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Diffstat (limited to 'onlineupdate/source/libmar/inc/mozilla/TypeTraits.h')
| -rw-r--r-- | onlineupdate/source/libmar/inc/mozilla/TypeTraits.h | 1116 |
1 files changed, 0 insertions, 1116 deletions
diff --git a/onlineupdate/source/libmar/inc/mozilla/TypeTraits.h b/onlineupdate/source/libmar/inc/mozilla/TypeTraits.h deleted file mode 100644 index 47c7945a6a2d..000000000000 --- a/onlineupdate/source/libmar/inc/mozilla/TypeTraits.h +++ /dev/null @@ -1,1116 +0,0 @@ -/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ -/* vim: set ts=8 sts=2 et sw=2 tw=80: */ -/* This Source Code Form is subject to the terms of the Mozilla Public - * License, v. 2.0. If a copy of the MPL was not distributed with this - * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ - -/* Template-based metaprogramming and type-testing facilities. */ - -#ifndef mozilla_TypeTraits_h -#define mozilla_TypeTraits_h - -#include "mozilla/Types.h" - -/* - * These traits are approximate copies of the traits and semantics from C++11's - * <type_traits> header. Don't add traits not in that header! When all - * platforms provide that header, we can convert all users and remove this one. - */ - -#include <wchar.h> - -namespace mozilla { - -/* Forward declarations. */ - -template<typename> struct RemoveCV; - -/* 20.9.3 Helper classes [meta.help] */ - -/** - * Helper class used as a base for various type traits, exposed publicly - * because <type_traits> exposes it as well. - */ -template<typename T, T Value> -struct IntegralConstant -{ - static const T value = Value; - typedef T ValueType; - typedef IntegralConstant<T, Value> Type; -}; - -/** Convenient aliases. */ -typedef IntegralConstant<bool, true> TrueType; -typedef IntegralConstant<bool, false> FalseType; - -/* 20.9.4 Unary type traits [meta.unary] */ - -/* 20.9.4.1 Primary type categories [meta.unary.cat] */ - -namespace detail { - -template<typename T> -struct IsVoidHelper : FalseType {}; - -template<> -struct IsVoidHelper<void> : TrueType {}; - -} // namespace detail - -/** - * IsVoid determines whether a type is void. - * - * mozilla::IsVoid<int>::value is false; - * mozilla::IsVoid<void>::value is true; - * mozilla::IsVoid<void*>::value is false; - * mozilla::IsVoid<volatile void>::value is true. - */ -template<typename T> -struct IsVoid : detail::IsVoidHelper<typename RemoveCV<T>::Type> {}; - -namespace detail { - -template <typename T> -struct IsIntegralHelper : FalseType {}; - -template<> struct IsIntegralHelper<char> : TrueType {}; -template<> struct IsIntegralHelper<signed char> : TrueType {}; -template<> struct IsIntegralHelper<unsigned char> : TrueType {}; -template<> struct IsIntegralHelper<short> : TrueType {}; -template<> struct IsIntegralHelper<unsigned short> : TrueType {}; -template<> struct IsIntegralHelper<int> : TrueType {}; -template<> struct IsIntegralHelper<unsigned int> : TrueType {}; -template<> struct IsIntegralHelper<long> : TrueType {}; -template<> struct IsIntegralHelper<unsigned long> : TrueType {}; -template<> struct IsIntegralHelper<long long> : TrueType {}; -template<> struct IsIntegralHelper<unsigned long long> : TrueType {}; -template<> struct IsIntegralHelper<bool> : TrueType {}; -template<> struct IsIntegralHelper<wchar_t> : TrueType {}; -#ifdef MOZ_CHAR16_IS_NOT_WCHAR -template<> struct IsIntegralHelper<char16_t> : TrueType {}; -#endif - -} /* namespace detail */ - -/** - * IsIntegral determines whether a type is an integral type. - * - * mozilla::IsIntegral<int>::value is true; - * mozilla::IsIntegral<unsigned short>::value is true; - * mozilla::IsIntegral<const long>::value is true; - * mozilla::IsIntegral<int*>::value is false; - * mozilla::IsIntegral<double>::value is false; - * - * Note that the behavior of IsIntegral on char16_t and char32_t is - * unspecified. - */ -template<typename T> -struct IsIntegral : detail::IsIntegralHelper<typename RemoveCV<T>::Type> -{}; - -template<typename T, typename U> -struct IsSame; - -namespace detail { - -template<typename T> -struct IsFloatingPointHelper - : IntegralConstant<bool, - IsSame<T, float>::value || - IsSame<T, double>::value || - IsSame<T, long double>::value> -{}; - -} // namespace detail - -/** - * IsFloatingPoint determines whether a type is a floating point type (float, - * double, long double). - * - * mozilla::IsFloatingPoint<int>::value is false; - * mozilla::IsFloatingPoint<const float>::value is true; - * mozilla::IsFloatingPoint<long double>::value is true; - * mozilla::IsFloatingPoint<double*>::value is false. - */ -template<typename T> -struct IsFloatingPoint - : detail::IsFloatingPointHelper<typename RemoveCV<T>::Type> -{}; - -namespace detail { - -template<typename T> -struct IsArrayHelper : FalseType {}; - -template<typename T, decltype(sizeof(1)) N> -struct IsArrayHelper<T[N]> : TrueType {}; - -template<typename T> -struct IsArrayHelper<T[]> : TrueType {}; - -} // namespace detail - -/** - * IsArray determines whether a type is an array type, of known or unknown - * length. - * - * mozilla::IsArray<int>::value is false; - * mozilla::IsArray<int[]>::value is true; - * mozilla::IsArray<int[5]>::value is true. - */ -template<typename T> -struct IsArray : detail::IsArrayHelper<typename RemoveCV<T>::Type> -{}; - -namespace detail { - -template<typename T> -struct IsPointerHelper : FalseType {}; - -template<typename T> -struct IsPointerHelper<T*> : TrueType {}; - -} // namespace detail - -/** - * IsPointer determines whether a type is a possibly-CV-qualified pointer type - * (but not a pointer-to-member type). - * - * mozilla::IsPointer<struct S*>::value is true; - * mozilla::IsPointer<int*>::value is true; - * mozilla::IsPointer<int**>::value is true; - * mozilla::IsPointer<const int*>::value is true; - * mozilla::IsPointer<int* const>::value is true; - * mozilla::IsPointer<int* volatile>::value is true; - * mozilla::IsPointer<void (*)(void)>::value is true; - * mozilla::IsPointer<int>::value is false; - * mozilla::IsPointer<struct S>::value is false. - * mozilla::IsPointer<int(struct S::*)>::value is false - */ -template<typename T> -struct IsPointer : detail::IsPointerHelper<typename RemoveCV<T>::Type> -{}; - -/** - * IsLvalueReference determines whether a type is an lvalue reference. - * - * mozilla::IsLvalueReference<struct S*>::value is false; - * mozilla::IsLvalueReference<int**>::value is false; - * mozilla::IsLvalueReference<void (*)(void)>::value is false; - * mozilla::IsLvalueReference<int>::value is false; - * mozilla::IsLvalueReference<struct S>::value is false; - * mozilla::IsLvalueReference<struct S*&>::value is true; - * mozilla::IsLvalueReference<struct S&&>::value is false. - */ -template<typename T> -struct IsLvalueReference : FalseType {}; - -template<typename T> -struct IsLvalueReference<T&> : TrueType {}; - -/** - * IsRvalueReference determines whether a type is an rvalue reference. - * - * mozilla::IsRvalueReference<struct S*>::value is false; - * mozilla::IsRvalueReference<int**>::value is false; - * mozilla::IsRvalueReference<void (*)(void)>::value is false; - * mozilla::IsRvalueReference<int>::value is false; - * mozilla::IsRvalueReference<struct S>::value is false; - * mozilla::IsRvalueReference<struct S*&>::value is false; - * mozilla::IsRvalueReference<struct S&&>::value is true. - */ -template<typename T> -struct IsRvalueReference : FalseType {}; - -template<typename T> -struct IsRvalueReference<T&&> : TrueType {}; - -namespace detail { - -// __is_enum is a supported extension across all of our supported compilers. -template<typename T> -struct IsEnumHelper - : IntegralConstant<bool, __is_enum(T)> -{}; - -} // namespace detail - -/** - * IsEnum determines whether a type is an enum type. - * - * mozilla::IsEnum<enum S>::value is true; - * mozilla::IsEnum<enum S*>::value is false; - * mozilla::IsEnum<int>::value is false; - */ -template<typename T> -struct IsEnum - : detail::IsEnumHelper<typename RemoveCV<T>::Type> -{}; - -namespace detail { - -// __is_class is a supported extension across all of our supported compilers: -// http://llvm.org/releases/3.0/docs/ClangReleaseNotes.html -// http://gcc.gnu.org/onlinedocs/gcc-4.4.7/gcc/Type-Traits.html#Type-Traits -// http://msdn.microsoft.com/en-us/library/ms177194%28v=vs.100%29.aspx -template<typename T> -struct IsClassHelper - : IntegralConstant<bool, __is_class(T)> -{}; - -} // namespace detail - -/** - * IsClass determines whether a type is a class type (but not a union). - * - * struct S {}; - * union U {}; - * mozilla::IsClass<int>::value is false; - * mozilla::IsClass<const S>::value is true; - * mozilla::IsClass<U>::value is false; - */ -template<typename T> -struct IsClass - : detail::IsClassHelper<typename RemoveCV<T>::Type> -{}; - -/* 20.9.4.2 Composite type traits [meta.unary.comp] */ - -/** - * IsReference determines whether a type is an lvalue or rvalue reference. - * - * mozilla::IsReference<struct S*>::value is false; - * mozilla::IsReference<int**>::value is false; - * mozilla::IsReference<int&>::value is true; - * mozilla::IsReference<void (*)(void)>::value is false; - * mozilla::IsReference<const int&>::value is true; - * mozilla::IsReference<int>::value is false; - * mozilla::IsReference<struct S>::value is false; - * mozilla::IsReference<struct S&>::value is true; - * mozilla::IsReference<struct S*&>::value is true; - * mozilla::IsReference<struct S&&>::value is true. - */ -template<typename T> -struct IsReference - : IntegralConstant<bool, - IsLvalueReference<T>::value || IsRvalueReference<T>::value> -{}; - -/** - * IsArithmetic determines whether a type is arithmetic. A type is arithmetic - * iff it is an integral type or a floating point type. - * - * mozilla::IsArithmetic<int>::value is true; - * mozilla::IsArithmetic<double>::value is true; - * mozilla::IsArithmetic<long double*>::value is false. - */ -template<typename T> -struct IsArithmetic - : IntegralConstant<bool, IsIntegral<T>::value || IsFloatingPoint<T>::value> -{}; - -/* 20.9.4.3 Type properties [meta.unary.prop] */ - -/** - * IsConst determines whether a type is const or not. - * - * mozilla::IsConst<int>::value is false; - * mozilla::IsConst<void* const>::value is true; - * mozilla::IsConst<const char*>::value is false. - */ -template<typename T> -struct IsConst : FalseType {}; - -template<typename T> -struct IsConst<const T> : TrueType {}; - -/** - * IsVolatile determines whether a type is volatile or not. - * - * mozilla::IsVolatile<int>::value is false; - * mozilla::IsVolatile<void* volatile>::value is true; - * mozilla::IsVolatile<volatile char*>::value is false. - */ -template<typename T> -struct IsVolatile : FalseType {}; - -template<typename T> -struct IsVolatile<volatile T> : TrueType {}; - -/** - * Traits class for identifying POD types. Until C++11 there's no automatic - * way to detect PODs, so for the moment this is done manually. Users may - * define specializations of this class that inherit from mozilla::TrueType and - * mozilla::FalseType (or equivalently mozilla::IntegralConstant<bool, true or - * false>, or conveniently from mozilla::IsPod for composite types) as needed to - * ensure correct IsPod behavior. - */ -template<typename T> -struct IsPod : public FalseType {}; - -template<> struct IsPod<char> : TrueType {}; -template<> struct IsPod<signed char> : TrueType {}; -template<> struct IsPod<unsigned char> : TrueType {}; -template<> struct IsPod<short> : TrueType {}; -template<> struct IsPod<unsigned short> : TrueType {}; -template<> struct IsPod<int> : TrueType {}; -template<> struct IsPod<unsigned int> : TrueType {}; -template<> struct IsPod<long> : TrueType {}; -template<> struct IsPod<unsigned long> : TrueType {}; -template<> struct IsPod<long long> : TrueType {}; -template<> struct IsPod<unsigned long long> : TrueType {}; -template<> struct IsPod<bool> : TrueType {}; -template<> struct IsPod<float> : TrueType {}; -template<> struct IsPod<double> : TrueType {}; -template<> struct IsPod<wchar_t> : TrueType {}; -#ifdef MOZ_CHAR16_IS_NOT_WCHAR -template<> struct IsPod<char16_t> : TrueType {}; -#endif -template<typename T> struct IsPod<T*> : TrueType {}; - -namespace detail { - -// __is_empty is a supported extension across all of our supported compilers: -// http://llvm.org/releases/3.0/docs/ClangReleaseNotes.html -// http://gcc.gnu.org/onlinedocs/gcc-4.4.7/gcc/Type-Traits.html#Type-Traits -// http://msdn.microsoft.com/en-us/library/ms177194%28v=vs.100%29.aspx -template<typename T> -struct IsEmptyHelper - : IntegralConstant<bool, IsClass<T>::value && __is_empty(T)> -{}; - -} // namespace detail - -/** - * IsEmpty determines whether a type is a class (but not a union) that is empty. - * - * A class is empty iff it and all its base classes have no non-static data - * members (except bit-fields of length 0) and no virtual member functions, and - * no base class is empty or a virtual base class. - * - * Intuitively, empty classes don't have any data that has to be stored in - * instances of those classes. (The size of the class must still be non-zero, - * because distinct array elements of any type must have different addresses. - * However, if the Empty Base Optimization is implemented by the compiler [most - * compilers implement it, and in certain cases C++11 requires it], the size of - * a class inheriting from an empty |Base| class need not be inflated by - * |sizeof(Base)|.) And intuitively, non-empty classes have data members and/or - * vtable pointers that must be stored in each instance for proper behavior. - * - * static_assert(!mozilla::IsEmpty<int>::value, "not a class => not empty"); - * union U1 { int x; }; - * static_assert(!mozilla::IsEmpty<U1>::value, "not a class => not empty"); - * struct E1 {}; - * struct E2 { int : 0 }; - * struct E3 : E1 {}; - * struct E4 : E2 {}; - * static_assert(mozilla::IsEmpty<E1>::value && - * mozilla::IsEmpty<E2>::value && - * mozilla::IsEmpty<E3>::value && - * mozilla::IsEmpty<E4>::value, - * "all empty"); - * union U2 { E1 e1; }; - * static_assert(!mozilla::IsEmpty<U2>::value, "not a class => not empty"); - * struct NE1 { int x; }; - * struct NE2 : virtual E1 {}; - * struct NE3 : E2 { virtual ~NE3() {} }; - * struct NE4 { virtual void f() {} }; - * static_assert(!mozilla::IsEmpty<NE1>::value && - * !mozilla::IsEmpty<NE2>::value && - * !mozilla::IsEmpty<NE3>::value && - * !mozilla::IsEmpty<NE4>::value, - * "all empty"); - */ -template<typename T> -struct IsEmpty : detail::IsEmptyHelper<typename RemoveCV<T>::Type> -{}; - - -namespace detail { - -template<typename T, - bool = IsFloatingPoint<T>::value, - bool = IsIntegral<T>::value, - typename NoCV = typename RemoveCV<T>::Type> -struct IsSignedHelper; - -// Floating point is signed. -template<typename T, typename NoCV> -struct IsSignedHelper<T, true, false, NoCV> : TrueType {}; - -// Integral is conditionally signed. -template<typename T, typename NoCV> -struct IsSignedHelper<T, false, true, NoCV> - : IntegralConstant<bool, bool(NoCV(-1) < NoCV(1))> -{}; - -// Non-floating point, non-integral is not signed. -template<typename T, typename NoCV> -struct IsSignedHelper<T, false, false, NoCV> : FalseType {}; - -} // namespace detail - -/** - * IsSigned determines whether a type is a signed arithmetic type. |char| is - * considered a signed type if it has the same representation as |signed char|. - * - * mozilla::IsSigned<int>::value is true; - * mozilla::IsSigned<const unsigned int>::value is false; - * mozilla::IsSigned<unsigned char>::value is false; - * mozilla::IsSigned<float>::value is true. - */ -template<typename T> -struct IsSigned : detail::IsSignedHelper<T> {}; - -namespace detail { - -template<typename T, - bool = IsFloatingPoint<T>::value, - bool = IsIntegral<T>::value, - typename NoCV = typename RemoveCV<T>::Type> -struct IsUnsignedHelper; - -// Floating point is not unsigned. -template<typename T, typename NoCV> -struct IsUnsignedHelper<T, true, false, NoCV> : FalseType {}; - -// Integral is conditionally unsigned. -template<typename T, typename NoCV> -struct IsUnsignedHelper<T, false, true, NoCV> - : IntegralConstant<bool, - (IsSame<NoCV, bool>::value || bool(NoCV(1) < NoCV(-1)))> -{}; - -// Non-floating point, non-integral is not unsigned. -template<typename T, typename NoCV> -struct IsUnsignedHelper<T, false, false, NoCV> : FalseType {}; - -} // namespace detail - -/** - * IsUnsigned determines whether a type is an unsigned arithmetic type. - * - * mozilla::IsUnsigned<int>::value is false; - * mozilla::IsUnsigned<const unsigned int>::value is true; - * mozilla::IsUnsigned<unsigned char>::value is true; - * mozilla::IsUnsigned<float>::value is false. - */ -template<typename T> -struct IsUnsigned : detail::IsUnsignedHelper<T> {}; - -/* 20.9.5 Type property queries [meta.unary.prop.query] */ - -/* 20.9.6 Relationships between types [meta.rel] */ - -/** - * IsSame tests whether two types are the same type. - * - * mozilla::IsSame<int, int>::value is true; - * mozilla::IsSame<int*, int*>::value is true; - * mozilla::IsSame<int, unsigned int>::value is false; - * mozilla::IsSame<void, void>::value is true; - * mozilla::IsSame<const int, int>::value is false; - * mozilla::IsSame<struct S, struct S>::value is true. - */ -template<typename T, typename U> -struct IsSame : FalseType {}; - -template<typename T> -struct IsSame<T, T> : TrueType {}; - -namespace detail { - -#if defined(__GNUC__) || defined(__clang__) || defined(_MSC_VER) - -template<class Base, class Derived> -struct BaseOfTester : IntegralConstant<bool, __is_base_of(Base, Derived)> {}; - -#else - -// The trickery used to implement IsBaseOf here makes it possible to use it for -// the cases of private and multiple inheritance. This code was inspired by the -// sample code here: -// -// http://stackoverflow.com/questions/2910979/how-is-base-of-works -template<class Base, class Derived> -struct BaseOfHelper -{ -public: - operator Base*() const; - operator Derived*(); -}; - -template<class Base, class Derived> -struct BaseOfTester -{ -private: - template<class T> - static char test(Derived*, T); - static int test(Base*, int); - -public: - static const bool value = - sizeof(test(BaseOfHelper<Base, Derived>(), int())) == sizeof(char); -}; - -template<class Base, class Derived> -struct BaseOfTester<Base, const Derived> -{ -private: - template<class T> - static char test(Derived*, T); - static int test(Base*, int); - -public: - static const bool value = - sizeof(test(BaseOfHelper<Base, Derived>(), int())) == sizeof(char); -}; - -template<class Base, class Derived> -struct BaseOfTester<Base&, Derived&> : FalseType {}; - -template<class Type> -struct BaseOfTester<Type, Type> : TrueType {}; - -template<class Type> -struct BaseOfTester<Type, const Type> : TrueType {}; - -#endif - -} /* namespace detail */ - -/* - * IsBaseOf allows to know whether a given class is derived from another. - * - * Consider the following class definitions: - * - * class A {}; - * class B : public A {}; - * class C {}; - * - * mozilla::IsBaseOf<A, B>::value is true; - * mozilla::IsBaseOf<A, C>::value is false; - */ -template<class Base, class Derived> -struct IsBaseOf - : IntegralConstant<bool, detail::BaseOfTester<Base, Derived>::value> -{}; - -namespace detail { - -template<typename From, typename To> -struct ConvertibleTester -{ -private: - static From create(); - - template<typename From1, typename To1> - static char test(To to); - - template<typename From1, typename To1> - static int test(...); - -public: - static const bool value = - sizeof(test<From, To>(create())) == sizeof(char); -}; - -} // namespace detail - -/** - * IsConvertible determines whether a value of type From will implicitly convert - * to a value of type To. For example: - * - * struct A {}; - * struct B : public A {}; - * struct C {}; - * - * mozilla::IsConvertible<A, A>::value is true; - * mozilla::IsConvertible<A*, A*>::value is true; - * mozilla::IsConvertible<B, A>::value is true; - * mozilla::IsConvertible<B*, A*>::value is true; - * mozilla::IsConvertible<C, A>::value is false; - * mozilla::IsConvertible<A, C>::value is false; - * mozilla::IsConvertible<A*, C*>::value is false; - * mozilla::IsConvertible<C*, A*>::value is false. - * - * For obscure reasons, you can't use IsConvertible when the types being tested - * are related through private inheritance, and you'll get a compile error if - * you try. Just don't do it! - * - * Note - we need special handling for void, which ConvertibleTester doesn't - * handle. The void handling here doesn't handle const/volatile void correctly, - * which could be easily fixed if the need arises. - */ -template<typename From, typename To> -struct IsConvertible - : IntegralConstant<bool, detail::ConvertibleTester<From, To>::value> -{}; - -template<typename B> -struct IsConvertible<void, B> - : IntegralConstant<bool, IsVoid<B>::value> -{}; - -template<typename A> -struct IsConvertible<A, void> - : IntegralConstant<bool, IsVoid<A>::value> -{}; - -template<> -struct IsConvertible<void, void> - : TrueType -{}; - -/* 20.9.7 Transformations between types [meta.trans] */ - -/* 20.9.7.1 Const-volatile modifications [meta.trans.cv] */ - -/** - * RemoveConst removes top-level const qualifications on a type. - * - * mozilla::RemoveConst<int>::Type is int; - * mozilla::RemoveConst<const int>::Type is int; - * mozilla::RemoveConst<const int*>::Type is const int*; - * mozilla::RemoveConst<int* const>::Type is int*. - */ -template<typename T> -struct RemoveConst -{ - typedef T Type; -}; - -template<typename T> -struct RemoveConst<const T> -{ - typedef T Type; -}; - -/** - * RemoveVolatile removes top-level volatile qualifications on a type. - * - * mozilla::RemoveVolatile<int>::Type is int; - * mozilla::RemoveVolatile<volatile int>::Type is int; - * mozilla::RemoveVolatile<volatile int*>::Type is volatile int*; - * mozilla::RemoveVolatile<int* volatile>::Type is int*. - */ -template<typename T> -struct RemoveVolatile -{ - typedef T Type; -}; - -template<typename T> -struct RemoveVolatile<volatile T> -{ - typedef T Type; -}; - -/** - * RemoveCV removes top-level const and volatile qualifications on a type. - * - * mozilla::RemoveCV<int>::Type is int; - * mozilla::RemoveCV<const int>::Type is int; - * mozilla::RemoveCV<volatile int>::Type is int; - * mozilla::RemoveCV<int* const volatile>::Type is int*. - */ -template<typename T> -struct RemoveCV -{ - typedef typename RemoveConst<typename RemoveVolatile<T>::Type>::Type Type; -}; - -/* 20.9.7.2 Reference modifications [meta.trans.ref] */ - -/** - * Converts reference types to the underlying types. - * - * mozilla::RemoveReference<T>::Type is T; - * mozilla::RemoveReference<T&>::Type is T; - * mozilla::RemoveReference<T&&>::Type is T; - */ - -template<typename T> -struct RemoveReference -{ - typedef T Type; -}; - -template<typename T> -struct RemoveReference<T&> -{ - typedef T Type; -}; - -template<typename T> -struct RemoveReference<T&&> -{ - typedef T Type; -}; - -template<bool Condition, typename A, typename B> -struct Conditional; - -namespace detail { - -enum Voidness { TIsVoid, TIsNotVoid }; - -template<typename T, Voidness V = IsVoid<T>::value ? TIsVoid : TIsNotVoid> -struct AddLvalueReferenceHelper; - -template<typename T> -struct AddLvalueReferenceHelper<T, TIsVoid> -{ - typedef void Type; -}; - -template<typename T> -struct AddLvalueReferenceHelper<T, TIsNotVoid> -{ - typedef T& Type; -}; - -} // namespace detail - -/** - * AddLvalueReference adds an lvalue & reference to T if one isn't already - * present. (Note: adding an lvalue reference to an rvalue && reference in - * essence replaces the && with a &&, per C+11 reference collapsing rules. For - * example, int&& would become int&.) - * - * The final computed type will only *not* be an lvalue reference if T is void. - * - * mozilla::AddLvalueReference<int>::Type is int&; - * mozilla::AddLvalueRference<volatile int&>::Type is volatile int&; - * mozilla::AddLvalueReference<void*>::Type is void*&; - * mozilla::AddLvalueReference<void>::Type is void; - * mozilla::AddLvalueReference<struct S&&>::Type is struct S&. - */ -template<typename T> -struct AddLvalueReference - : detail::AddLvalueReferenceHelper<T> -{}; - -namespace detail { - -template<typename T, Voidness V = IsVoid<T>::value ? TIsVoid : TIsNotVoid> -struct AddRvalueReferenceHelper; - -template<typename T> -struct AddRvalueReferenceHelper<T, TIsVoid> -{ - typedef void Type; -}; - -template<typename T> -struct AddRvalueReferenceHelper<T, TIsNotVoid> -{ - typedef T&& Type; -}; - -} // namespace detail - -/** - * AddRvalueReference adds an rvalue && reference to T if one isn't already - * present. (Note: adding an rvalue reference to an lvalue & reference in - * essence keeps the &, per C+11 reference collapsing rules. For example, - * int& would remain int&.) - * - * The final computed type will only *not* be a reference if T is void. - * - * mozilla::AddRvalueReference<int>::Type is int&&; - * mozilla::AddRvalueRference<volatile int&>::Type is volatile int&; - * mozilla::AddRvalueRference<const int&&>::Type is const int&&; - * mozilla::AddRvalueReference<void*>::Type is void*&&; - * mozilla::AddRvalueReference<void>::Type is void; - * mozilla::AddRvalueReference<struct S&>::Type is struct S&. - */ -template<typename T> -struct AddRvalueReference - : detail::AddRvalueReferenceHelper<T> -{}; - -/* 20.2.4 Function template declval [declval] */ - -/** - * DeclVal simplifies the definition of expressions which occur as unevaluated - * operands. It converts T to a reference type, making it possible to use in - * decltype expressions even if T does not have a default constructor, e.g.: - * decltype(DeclVal<TWithNoDefaultConstructor>().foo()) - */ -template<typename T> -typename AddRvalueReference<T>::Type DeclVal(); - -/* 20.9.7.3 Sign modifications [meta.trans.sign] */ - -template<bool B, typename T = void> -struct EnableIf; - -namespace detail { - -template<bool MakeConst, typename T> -struct WithC : Conditional<MakeConst, const T, T> -{}; - -template<bool MakeVolatile, typename T> -struct WithV : Conditional<MakeVolatile, volatile T, T> -{}; - - -template<bool MakeConst, bool MakeVolatile, typename T> -struct WithCV : WithC<MakeConst, typename WithV<MakeVolatile, T>::Type> -{}; - -template<typename T> -struct CorrespondingSigned; - -template<> -struct CorrespondingSigned<char> { typedef signed char Type; }; -template<> -struct CorrespondingSigned<unsigned char> { typedef signed char Type; }; -template<> -struct CorrespondingSigned<unsigned short> { typedef short Type; }; -template<> -struct CorrespondingSigned<unsigned int> { typedef int Type; }; -template<> -struct CorrespondingSigned<unsigned long> { typedef long Type; }; -template<> -struct CorrespondingSigned<unsigned long long> { typedef long long Type; }; - -template<typename T, - typename CVRemoved = typename RemoveCV<T>::Type, - bool IsSignedIntegerType = IsSigned<CVRemoved>::value && - !IsSame<char, CVRemoved>::value> -struct MakeSigned; - -template<typename T, typename CVRemoved> -struct MakeSigned<T, CVRemoved, true> -{ - typedef T Type; -}; - -template<typename T, typename CVRemoved> -struct MakeSigned<T, CVRemoved, false> - : WithCV<IsConst<T>::value, IsVolatile<T>::value, - typename CorrespondingSigned<CVRemoved>::Type> -{}; - -} // namespace detail - -/** - * MakeSigned produces the corresponding signed integer type for a given - * integral type T, with the const/volatile qualifiers of T. T must be a - * possibly-const/volatile-qualified integral type that isn't bool. - * - * If T is already a signed integer type (not including char!), then T is - * produced. - * - * Otherwise, if T is an unsigned integer type, the signed variety of T, with - * T's const/volatile qualifiers, is produced. - * - * Otherwise, the integral type of the same size as T, with the lowest rank, - * with T's const/volatile qualifiers, is produced. (This basically only acts - * to produce signed char when T = char.) - * - * mozilla::MakeSigned<unsigned long>::Type is signed long; - * mozilla::MakeSigned<volatile int>::Type is volatile int; - * mozilla::MakeSigned<const unsigned short>::Type is const signed short; - * mozilla::MakeSigned<const char>::Type is const signed char; - * mozilla::MakeSigned<bool> is an error; - * mozilla::MakeSigned<void*> is an error. - */ -template<typename T> -struct MakeSigned - : EnableIf<IsIntegral<T>::value && - !IsSame<bool, typename RemoveCV<T>::Type>::value, - typename detail::MakeSigned<T> - >::Type -{}; - -namespace detail { - -template<typename T> -struct CorrespondingUnsigned; - -template<> -struct CorrespondingUnsigned<char> { typedef unsigned char Type; }; -template<> -struct CorrespondingUnsigned<signed char> { typedef unsigned char Type; }; -template<> -struct CorrespondingUnsigned<short> { typedef unsigned short Type; }; -template<> -struct CorrespondingUnsigned<int> { typedef unsigned int Type; }; -template<> -struct CorrespondingUnsigned<long> { typedef unsigned long Type; }; -template<> -struct CorrespondingUnsigned<long long> { typedef unsigned long long Type; }; - - -template<typename T, - typename CVRemoved = typename RemoveCV<T>::Type, - bool IsUnsignedIntegerType = IsUnsigned<CVRemoved>::value && - !IsSame<char, CVRemoved>::value> -struct MakeUnsigned; - -template<typename T, typename CVRemoved> -struct MakeUnsigned<T, CVRemoved, true> -{ - typedef T Type; -}; - -template<typename T, typename CVRemoved> -struct MakeUnsigned<T, CVRemoved, false> - : WithCV<IsConst<T>::value, IsVolatile<T>::value, - typename CorrespondingUnsigned<CVRemoved>::Type> -{}; - -} // namespace detail - -/** - * MakeUnsigned produces the corresponding unsigned integer type for a given - * integral type T, with the const/volatile qualifiers of T. T must be a - * possibly-const/volatile-qualified integral type that isn't bool. - * - * If T is already an unsigned integer type (not including char!), then T is - * produced. - * - * Otherwise, if T is an signed integer type, the unsigned variety of T, with - * T's const/volatile qualifiers, is produced. - * - * Otherwise, the unsigned integral type of the same size as T, with the lowest - * rank, with T's const/volatile qualifiers, is produced. (This basically only - * acts to produce unsigned char when T = char.) - * - * mozilla::MakeUnsigned<signed long>::Type is unsigned long; - * mozilla::MakeUnsigned<volatile unsigned int>::Type is volatile unsigned int; - * mozilla::MakeUnsigned<const signed short>::Type is const unsigned short; - * mozilla::MakeUnsigned<const char>::Type is const unsigned char; - * mozilla::MakeUnsigned<bool> is an error; - * mozilla::MakeUnsigned<void*> is an error. - */ -template<typename T> -struct MakeUnsigned - : EnableIf<IsIntegral<T>::value && - !IsSame<bool, typename RemoveCV<T>::Type>::value, - typename detail::MakeUnsigned<T> - >::Type -{}; - -/* 20.9.7.4 Array modifications [meta.trans.arr] */ - -/** - * RemoveExtent produces either the type of the elements of the array T, or T - * itself. - * - * mozilla::RemoveExtent<int>::Type is int; - * mozilla::RemoveExtent<const int[]>::Type is const int; - * mozilla::RemoveExtent<volatile int[5]>::Type is volatile int; - * mozilla::RemoveExtent<long[][17]>::Type is long[17]. - */ -template<typename T> -struct RemoveExtent -{ - typedef T Type; -}; - -template<typename T> -struct RemoveExtent<T[]> -{ - typedef T Type; -}; - -template<typename T, decltype(sizeof(1)) N> -struct RemoveExtent<T[N]> -{ - typedef T Type; -}; - -/* 20.9.7.5 Pointer modifications [meta.trans.ptr] */ - -namespace detail { - -template<typename T, typename CVRemoved> -struct RemovePointerHelper -{ - typedef T Type; -}; - -template<typename T, typename Pointee> -struct RemovePointerHelper<T, Pointee*> -{ - typedef Pointee Type; -}; - -} // namespac detail - -/** - * Produces the pointed-to type if a pointer is provided, else returns the input - * type. Note that this does not dereference pointer-to-member pointers. - * - * struct S { bool m; void f(); }; - * mozilla::RemovePointer<int>::Type is int; - * mozilla::RemovePointer<int*>::Type is int; - * mozilla::RemovePointer<int* const>::Type is int; - * mozilla::RemovePointer<int* volatile>::Type is int; - * mozilla::RemovePointer<const long*>::Type is const long; - * mozilla::RemovePointer<void* const>::Type is void; - * mozilla::RemovePointer<void (S::*)()>::Type is void (S::*)(); - * mozilla::RemovePointer<void (*)()>::Type is void(); - * mozilla::RemovePointer<bool S::*>::Type is bool S::*. - */ -template<typename T> -struct RemovePointer - : detail::RemovePointerHelper<T, typename RemoveCV<T>::Type> -{}; - -/* 20.9.7.6 Other transformations [meta.trans.other] */ - -/** - * EnableIf is a struct containing a typedef of T if and only if B is true. - * - * mozilla::EnableIf<true, int>::Type is int; - * mozilla::EnableIf<false, int>::Type is a compile-time error. - * - * Use this template to implement SFINAE-style (Substitution Failure Is not An - * Error) requirements. For example, you might use it to impose a restriction - * on a template parameter: - * - * template<typename T> - * class PodVector // vector optimized to store POD (memcpy-able) types - * { - * EnableIf<IsPod<T>::value, T>::Type* vector; - * size_t length; - * ... - * }; - */ -template<bool B, typename T> -struct EnableIf -{}; - -template<typename T> -struct EnableIf<true, T> -{ - typedef T Type; -}; - -/** - * Conditional selects a class between two, depending on a given boolean value. - * - * mozilla::Conditional<true, A, B>::Type is A; - * mozilla::Conditional<false, A, B>::Type is B; - */ -template<bool Condition, typename A, typename B> -struct Conditional -{ - typedef A Type; -}; - -template<class A, class B> -struct Conditional<false, A, B> -{ - typedef B Type; -}; - -} /* namespace mozilla */ - -#endif /* mozilla_TypeTraits_h */ |