Document all traits

This commit is contained in:
Marius Kittler 2018-07-10 13:17:26 +02:00
parent 9743dc7d28
commit 5e74deccf3
1 changed files with 32 additions and 0 deletions

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@ -13,65 +13,90 @@ enum class Enabler {};
}
/// \endcond
/// \brief Shortcut for std::conditional to omit ::value and ::type.
template <typename If, typename Then, typename Else> using Conditional = typename std::conditional<If::value, Then, Else>::type;
/// \brief Wraps a static boolean constant.
template <bool B, typename...> struct Bool : std::integral_constant<bool, B> {
};
/// \brief Negates the specified value.
template <typename T> using Not = Bool<!T::value>;
/// \brief Evaluates to Bool<true> if at least one of the specified conditions is true; otherwise evaluates to Bool<false>.
template <typename... T> struct Any : Bool<false> {
};
/// \brief Evaluates to Bool<true> if at least one of the specified conditions is true; otherwise evaluates to Bool<false>.
template <typename Head, typename... Tail> struct Any<Head, Tail...> : Conditional<Head, Bool<true>, Any<Tail...>> {
};
/// \brief Evaluates to Bool<true> if all specified conditions are true; otherwise evaluates to Bool<false>.
template <typename... T> struct All : Bool<true> {
};
/// \brief Evaluates to Bool<true> if all specified conditions are true; otherwise evaluates to Bool<false>.
template <typename Head, typename... Tail> struct All<Head, Tail...> : Conditional<Head, All<Tail...>, Bool<false>> {
};
/// \brief Evaluates to Bool<true> if none of the specified conditions are true; otherwise evaluates to Bool<false>.
template <typename... T> struct None : Bool<true> {
};
/// \brief Evaluates to Bool<true> if none of the specified conditions are true; otherwise evaluates to Bool<false>.
template <typename Head, typename... Tail> struct None<Head, Tail...> : Conditional<Head, Bool<false>, None<Tail...>> {
};
/// \brief Shortcut for std::enable_if to omit ::value and ::type.
template <typename... Condition> using EnableIf = typename std::enable_if<All<Condition...>::value, Detail::Enabler>::type;
/// \brief Shortcut for std::enable_if to negate the condition and omit ::value and ::type.
template <typename... Condition> using DisableIf = typename std::enable_if<!All<Condition...>::value, Detail::Enabler>::type;
/// \brief Shortcut for std::enable_if to apply Traits::Any and omit ::value and ::type.
template <typename... Condition> using EnableIfAny = typename std::enable_if<Any<Condition...>::value, Detail::Enabler>::type;
/// \brief Shortcut for std::enable_if to apply Traits::Any, negate the condition and omit ::value and ::type.
template <typename... Condition> using DisableIfAny = typename std::enable_if<!Any<Condition...>::value, Detail::Enabler>::type;
/// \brief Evaluates to Bool<true> if the specified type is based on the specified \tparam Template; otherwise evaluates to Bool<false>.
template <typename T, template <typename...> class Template> struct IsSpecializationOf : Bool<false> {
};
/// \brief Evaluates to Bool<true> if the specified type is based on the specified \tparam Template; otherwise evaluates to Bool<false>.
template <template <typename...> class Template, typename... Args> struct IsSpecializationOf<Template<Args...>, Template> : Bool<true> {
};
/// \brief Evaluates to Bool<true> if the specified type is based on one of the specified templates; otherwise evaluates to Bool<false>.
template <typename Type, template <typename...> class... TemplateTypes> struct IsSpecializingAnyOf : Bool<false> {
};
/// \brief Evaluates to Bool<true> if the specified type is based on one of the specified templates; otherwise evaluates to Bool<false>.
template <typename Type, template <typename...> class TemplateType, template <typename...> class... RemainingTemplateTypes>
struct IsSpecializingAnyOf<Type, TemplateType, RemainingTemplateTypes...>
: Conditional<IsSpecializationOf<Type, TemplateType>, Bool<true>, IsSpecializingAnyOf<Type, RemainingTemplateTypes...>> {
};
/// \brief Evaluates to Bool<true> if the specified type is any of the specified types; otherwise evaluates to Bool<false>.
template <typename... T> struct IsAnyOf : Bool<false> {
};
/// \brief Evaluates to Bool<true> if the specified type is any of the specified types; otherwise evaluates to Bool<false>.
template <typename Type, typename OtherType, typename... RemainingTypes>
struct IsAnyOf<Type, OtherType, RemainingTypes...> : Conditional<std::is_same<Type, OtherType>, Bool<true>, IsAnyOf<Type, RemainingTypes...>> {
};
/// \brief Evaluates to Bool<true> if the specified type is none of the specified types; otherwise evaluates to Bool<false>.
template <typename... T> struct IsNoneOf : Bool<true> {
};
/// \brief Evaluates to Bool<true> if the specified type is none of the specified types; otherwise evaluates to Bool<false>.
template <typename Type, typename OtherType, typename... RemainingTypes>
struct IsNoneOf<Type, OtherType, RemainingTypes...> : Conditional<std::is_same<Type, OtherType>, Bool<false>, IsNoneOf<Type, RemainingTypes...>> {
};
/// \brief Evaluates to Bool<true> if the specified type is a C-string (char * or const char *); otherwise evaluates to Bool<false>.
template <typename T>
struct IsCString
: Bool<std::is_same<char const *, typename std::decay<T>::type>::value || std::is_same<char *, typename std::decay<T>::type>::value> {
};
/// \brief Evaluates to Bool<true> if the specified type is a C-string (char * or const char *); otherwise evaluates to Bool<false>.
template <typename T> struct IsString : Bool<IsCString<T>::value || IsSpecializationOf<T, std::basic_string>::value> {
};
/// \brief Evaluates to Bool<true> if the specified type is complete; if the type is only forward-declared it evaluates to Bool<false>.
template <typename T, typename = void> struct IsComplete : Bool<false> {
};
/// \brief Evaluates to Bool<true> if the specified type is complete; if the type is only forward-declared it evaluates to Bool<false>.
template <typename T> struct IsComplete<T, decltype(void(sizeof(T)))> : Bool<true> {
};
@ -97,9 +122,16 @@ template <typename T> struct IsComplete<T, decltype(void(sizeof(T)))> : Bool<tru
/// \brief Evaluates to Bool<true> if the specified type can be dereferenced using the *-operator; otherwise evaluates to Bool<false>.
CPP_UTILITIES_TRAITS_DEFINE_TYPE_CHECK(IsDereferencable, *(std::declval<T &>()));
/// \brief Evaluates to Bool<true> if the specified type can has a size() method; otherwise evaluates to Bool<false>.
CPP_UTILITIES_TRAITS_DEFINE_TYPE_CHECK(HasSize, std::is_integral<decltype(std::declval<T &>().size())>::value);
/// \brief Evaluates to Bool<true> if the specified type can has a reserve() method; otherwise evaluates to Bool<false>.
CPP_UTILITIES_TRAITS_DEFINE_TYPE_CHECK(IsReservable, std::declval<T &>().reserve(0u));
/// \brief Evaluates to Bool<true> if the specified type can has a resize() method; otherwise evaluates to Bool<false>.
CPP_UTILITIES_TRAITS_DEFINE_TYPE_CHECK(IsResizable, std::declval<T &>().resize(0u));
/// \brief Evaluates to Bool<true> if the specified type is iteratable (can be used in for-each loop); otherwise evaluates to Bool<false>.
CPP_UTILITIES_TRAITS_DEFINE_TYPE_CHECK(IsIteratable,
// begin/end and operator !=
std::begin(std::declval<T &>())