Files
pilotclient/src/blackmisc/tuple_private.h
Mathew Sutcliffe f601334ffa refs #192 tweaking include order and moving some JSON things into global namespace
so that we invoke ADL instead of relying on a particular include order
2014-03-31 23:48:39 +01:00

274 lines
11 KiB
C++

/* Copyright (C) 2014 VATSIM Community / authors
* 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/. */
/*!
\file
Private implementation details used by tuple.h
*/
#ifndef BLACKMISC_TUPLE_PRIVATE_H
#define BLACKMISC_TUPLE_PRIVATE_H
#include <QtGlobal>
#include <QDBusArgument>
#include <QHash>
#include <QJsonObject>
#include <QDateTime>
#include <QString>
#include <QJsonArray>
#include <QDebug>
#include <tuple>
#include <type_traits>
#include <functional>
namespace BlackMisc
{
class CValueObject;
namespace Private
{
#ifdef Q_COMPILER_VARIADIC_TEMPLATES
// Helper trait to detect whether a class is a tuple.
//! \private
//! @{
template <class T>
struct IsTuple : public std::false_type {};
template <class... Ts>
struct IsTuple<std::tuple<Ts...>> : public std::true_type {};
//! @}
#else // !Q_COMPILER_VARIADIC_TEMPLATES
template <class T>
struct IsTuple : public std::false_type {};
template <>
struct IsTuple<std::tuple<>> : public std::true_type {};
template <class T0>
struct IsTuple<std::tuple<T0>> : public std::true_type {};
template <class T0, class T1>
struct IsTuple<std::tuple<T0, T1>> : public std::true_type {};
template <class T0, class T1, class T2>
struct IsTuple<std::tuple<T0, T1, T2>> : public std::true_type {};
template <class T0, class T1, class T2, class T3>
struct IsTuple<std::tuple<T0, T1, T2, T3>> : public std::true_type {};
template <class T0, class T1, class T2, class T3, class T4>
struct IsTuple<std::tuple<T0, T1, T2, T3, T4>> : public std::true_type {};
template <class T0, class T1, class T2, class T3, class T4, class T5>
struct IsTuple<std::tuple<T0, T1, T2, T3, T4, T5>> : public std::true_type {};
template <class T0, class T1, class T2, class T3, class T4, class T5, class T6>
struct IsTuple<std::tuple<T0, T1, T2, T3, T4, T5, T6>> : public std::true_type {};
template <class T0, class T1, class T2, class T3, class T4, class T5, class T6, class T7>
struct IsTuple<std::tuple<T0, T1, T2, T3, T4, T5, T6, T7>> : public std::true_type {};
template <class T0, class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8>
struct IsTuple<std::tuple<T0, T1, T2, T3, T4, T5, T6, T7, T8>> : public std::true_type {};
template <class T0, class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8, class T9>
struct IsTuple<std::tuple<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>> : public std::true_type {};
#endif // !Q_COMPILER_VARIADIC_TEMPLATES
// Using SFINAE to help detect missing BLACK_ENABLE_TUPLE_CONVERSION macro in static_assert
//! \private
std::false_type hasEnabledTupleConversionHelper(...);
//! \private
template <class T>
typename T::EnabledTupleConversion hasEnabledTupleConversionHelper(T *);
//! \private
template <class T>
struct HasEnabledTupleConversion
{
typedef decltype(hasEnabledTupleConversionHelper(static_cast<T *>(nullptr))) type;
static const bool value = type::value;
};
// Using tag dispatch to select which implementation of compare() to use
//! \private
//! @{
template <class T>
int compareHelper(const T &a, const T &b, std::true_type isCValueObjectTag)
{
Q_UNUSED(isCValueObjectTag);
return compare(a, b);
}
template <class T>
int compareHelper(const T &a, const T &b, std::false_type isCValueObjectTag)
{
Q_UNUSED(isCValueObjectTag);
if (a < b) { return -1; }
if (a > b) { return 1; }
return 0;
}
template <int N, class Tu>
int compareHelper(const Tu &a, const Tu &b)
{
typedef typename std::decay<typename std::tuple_element<N, Tu>::type>::type Element;
typedef std::integral_constant<bool, std::is_base_of<CValueObject, Element>::value || IsTuple<Element>::value> isCValueObjectTag;
return compareHelper(std::get<N>(a), std::get<N>(b), isCValueObjectTag());
}
//! @}
// Helper which returns a copy of its argument if it's a tuple,
// otherwise returns a reference to its argument.
//! \private
//! @{
template <class T>
auto tieHelper(T &obj, std::false_type isTupleTag) -> std::reference_wrapper<T>
{
Q_UNUSED(isTupleTag);
return obj;
}
template <class T>
auto tieHelper(T &obj, std::true_type isTupleTag) -> T
{
Q_UNUSED(isTupleTag);
return obj;
}
template <class T>
auto tieHelper(T &obj) -> decltype(tieHelper(obj, IsTuple<T>()))
{
return tieHelper(obj, IsTuple<T>());
}
//! @}
// Helper which (de)serializes its argument to/from JSON,
// whether it is a simple value or a nested tuple.
// Defined later because it uses TupleHelper;
// forward-declared because TupleHelper uses it.
//! \private
//! @{
template <class T>
static void serializeJsonHelper(QJsonObject &json, const QStringList &members, const T &obj, int index, std::false_type isNestedTag);
template <class T>
static void serializeJsonHelper(QJsonObject &json, const QStringList &members, const T &obj, int index, std::true_type isNestedTag);
template <class T>
static void serializeJsonHelper(QJsonObject &json, const QStringList &members, const T &obj, int index);
template <class T>
static void deserializeJsonHelper(const QJsonObject &json, const QStringList &members, T &obj, int index, std::false_type isNestedTag);
template <class T>
static void deserializeJsonHelper(const QJsonObject &json, const QStringList &members, T &obj, int index, std::true_type isNestedTag);
template <class T>
static void deserializeJsonHelper(const QJsonObject &json, const QStringList &members, T &obj, int index);
//! @}
// Applying operations to all elements in a tuple, using recursion
//! \private
template <int N>
struct TupleHelper
{
template <class Tu>
static int compare(const Tu &a, const Tu &b)
{
const int head = TupleHelper < N - 1 >::compare(a, b);
if (head) { return head; }
return compareHelper < N - 1 > (a, b);
}
template <class Tu>
static QDBusArgument &marshall(QDBusArgument &arg, const Tu &tu)
{
return TupleHelper < N - 1 >::marshall(arg, tu) << std::get < N - 1 > (tu);
}
template <class Tu>
static const QDBusArgument &unmarshall(const QDBusArgument &arg, Tu &tu)
{
return TupleHelper < N - 1 >::unmarshall(arg, tu) >> std::get < N - 1 > (tu);
}
template <class Tu>
static QDebug debug(QDebug dbg, Tu &tu)
{
return TupleHelper < N - 1 >::debug(dbg, tu) << std::get < N - 1 > (tu);
}
template <class Tu>
static uint hash(const Tu &tu)
{
return TupleHelper < N - 1 >::hash(tu) ^ qHash(std::get < N - 1 > (tu));
}
template <class Tu>
static void serializeJson(QJsonObject &json, const QStringList &members, const Tu &tu)
{
TupleHelper < N - 1 >::serializeJson(json, members, tu);
serializeJsonHelper(json, members, std::get < N - 1 > (tu), N - 1);
}
template <class Tu>
static void deserializeJson(const QJsonObject &json, const QStringList &members, Tu &tu)
{
TupleHelper < N - 1 >::deserializeJson(json, members, tu);
deserializeJsonHelper(json, members, std::get < N - 1 > (tu), N - 1);
}
};
//! \private
template <>
struct TupleHelper<0>
{
template <class Tu>
static int compare(const Tu &, const Tu &) { return 0; }
template <class Tu>
static QDBusArgument &marshall(QDBusArgument &arg, const Tu &) { return arg; }
template <class Tu>
static const QDBusArgument &unmarshall(const QDBusArgument &arg, Tu &) { return arg; }
template <class Tu>
static QDebug debug(QDebug dbg, Tu &) { return dbg; }
template <class Tu>
static uint hash(const Tu &) { return 0; }
template <class Tu>
static void serializeJson(QJsonObject &, const QStringList &, const Tu &) {}
template <class Tu>
static void deserializeJson(const QJsonObject &, const QStringList &, Tu &) {}
};
// definitions of helpers declared earlier
template <class T>
static void serializeJsonHelper(QJsonObject &json, const QStringList &members, const T &obj, int index, std::false_type isNestedTag)
{
Q_UNUSED(isNestedTag);
json << std::make_pair(members.at(index), obj);
}
template <class T>
static void serializeJsonHelper(QJsonObject &json, const QStringList &members, const T &obj, int index, std::true_type isNestedTag)
{
Q_UNUSED(isNestedTag);
TupleHelper<std::tuple_size<T>::value>::serializeJson(json, members.mid(index), obj);
}
template <class T>
static void serializeJsonHelper(QJsonObject &json, const QStringList &members, const T &obj, int index)
{
serializeJsonHelper(json, members, obj, index, IsTuple<T>());
}
template <class T>
static void deserializeJsonHelper(const QJsonObject &json, const QStringList &members, T &obj, int index, std::false_type isNestedTag)
{
Q_UNUSED(isNestedTag);
json.value(members.at(index)) >> obj;
}
template <class T>
static void deserializeJsonHelper(const QJsonObject &json, const QStringList &members, T &obj, int index, std::true_type isNestedTag)
{
Q_UNUSED(isNestedTag);
TupleHelper<std::tuple_size<T>::value>::deserializeJson(json, members.mid(index), obj);
}
template <class T>
static void deserializeJsonHelper(const QJsonObject &json, const QStringList &members, T &obj, int index)
{
deserializeJsonHelper(json, members, obj, index, IsTuple<T>());
}
} // namespace Private
} // namespace BlackMisc
#endif // guard