/*
 * Copyright (c) 2007 INRIA
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 */

#ifndef TYPE_TRAITS_H
#define TYPE_TRAITS_H

#include "deprecated.h"
#include "ptr.h"

/**
 *  @file
 *  @ingroup object
 *  ns3::TypeTraits introspection declaration and template implementation.
 */

namespace ns3
{

/**
 * @ingroup object
 *  Inspect a type to deduce its features.
 *  @tparam T \deduced The type to inspect.
 */
template <typename T>
struct NS_DEPRECATED_3_43("Use functions provided by #include <type_traits>") TypeTraits
{
  private:
    /** Null value type traits. */
    struct NullType
    {
    };

    /**
     *  Not a const type.
     *  @tparam U \deduced The type being inspected.
     */
    template <typename U>
    struct UnConst
    {
        typedef U Result; /**< Non-const type.       */
    };

    /**
     *  Const type.
     *  @tparam U \deduced The type being inspected.
     */
    template <typename U>
    struct UnConst<const U>
    {
        typedef U Result; /**< Non-const type.       */
    };

    /**
     *  Not a reference type.
     *  @tparam U \deduced The type being inspected.
     */
    template <typename U>
    struct ReferenceTraits
    {
        /** Value. */
        enum
        {
            IsReference = 0 /**< Not a reference type. */
        };

        typedef U ReferencedType; /**< Base type.            */
    };

    /**
     *  Reference type.
     *  @tparam U \deduced The type being inspected.
     */
    template <typename U>
    struct ReferenceTraits<U&>
    {
        /** Value. */
        enum
        {
            IsReference = 1 /**< Reference type.       */
        };

        typedef U ReferencedType; /**< Base type.            */
    };

    /**
     *  Not a pointer type.
     *  @tparam U \deduced The type being inspected.
     */
    template <typename U>
    struct PointerTraits
    {
        /** Value. */
        enum
        {
            IsPointer = 0, /**< Not a pointer type.   */
            IsPtr = 0      /**< Not a Ptr type.       */
        };

        typedef U PointeeType; /**< Base type.            */
    };

    /**
     *  Pointer type.
     *  @tparam U \deduced The type being inspected.
     */
    template <typename U>
    struct PointerTraits<U*>
    {
        /** Value. */
        enum
        {
            IsPointer = 1, /**< Pointer type.         */
            IsPtr = 0      /**< Not a Ptr type.       */
        };

        typedef U PointeeType; /**< Pointee type.         */
    };

    /**
     *  Ptr type.
     *  @tparam U \deduced The type being inspected.
     */
    template <typename U>
    struct PointerTraits<ns3::Ptr<U>>
    {
        /** Value. */
        enum
        {
            IsPointer = 0, /**< Not a pointer type.   */
            IsPtr = 1      /**< Ptr type.             */
        };

        typedef U PointeeType; /**< Pointee type.         */
    };

    /**
     * Base type, after removing \c &, \c * and \c const.
     * @tparam U \deduced The type being inspected.
     */
    template <typename U>
    struct Base
    {
        typedef U Type; /**< Base type.            */
    };

    /**
     * Base type, after removing \c &.
     * @tparam U \deduced The type being inspected.
     */
    template <typename U>
    struct Base<U&>
    {
        typedef typename Base<U>::Type Type; /**< Base type.            */
    };

    /**
     * Base type, after removing \c *.
     * @tparam U \deduced The type being inspected.
     */
    template <typename U>
    struct Base<U*>
    {
        typedef typename Base<U>::Type Type; /**< Base type.            */
    };

    /**
     * Base type, after removing \c const.
     * @tparam U \deduced The type being inspected.
     */
    template <typename U>
    struct Base<const U>
    {
        typedef typename Base<U>::Type Type; /**< Base type.            */
    };

    /**
     * Base type of a Ptr.
     * @tparam U \deduced The type being inspected.
     */
    template <typename U>
    struct PtrBase
    {
        typedef U Type; /**< Base type.            */
    };

    /**
     * Base type of a Ptr.
     * @tparam U \deduced The type being inspected.
     */
    template <typename U>
    struct PtrBase<ns3::Ptr<U>>
    {
        typedef U Type; /**< Base type.            */
    };

    /**
     *  Not a function pointer type.
     *  @tparam U \deduced The type being inspected.
     */
    template <typename U>
    struct FunctionPtrTraits
    {
        /** Value. */
        enum
        {
            IsFunctionPointer = 0 /**< Not a function pointer. */
        };

        typedef NullType ReturnType; /**< Return type.            */
    };

    /**
     *  Function pointer type.
     *  @tparam U \deduced Return type.
     */
    template <typename U>
    struct FunctionPtrTraits<U (*)()>
    {
        /** Value. */
        enum
        {
            IsFunctionPointer = 1 /**< Function pointer.     */
        };

        /** Value. */ enum
        {
            nArgs = 0 /**< Number of arguments.  */
        };

        typedef U ReturnType; /**< Return type.          */
    };

    /**
     *  Function pointer type.
     *  @tparam U \deduced Return type.
     *  @tparam V1 \deduced Argument type.
     */
    template <typename U, typename V1>
    struct FunctionPtrTraits<U (*)(V1)>
    {
        /** Value. */
        enum
        {
            IsFunctionPointer = 1 /**< Function pointer.     */
        };

        /** Value. */ enum
        {
            nArgs = 1 /**< Number of arguments.  */
        };

        typedef U ReturnType; /**< Return type.          */
        typedef V1 Arg1Type;  /**< First argument type.  */
    };

    /**
     *  Function pointer type.
     *  @tparam U \deduced Return type.
     *  @tparam V1 \deduced Argument type.
     *  @tparam V2 \deduced Argument type.
     */
    template <typename U, typename V1, typename V2>
    struct FunctionPtrTraits<U (*)(V1, V2)>
    {
        /** Value. */
        enum
        {
            IsFunctionPointer = 1 /**< Function pointer.     */
        };

        /** Value. */ enum
        {
            nArgs = 2 /**< Number of arguments.  */
        };

        typedef U ReturnType; /**< Return type.          */
        typedef V1 Arg1Type;  /**< First argument type.  */
        typedef V2 Arg2Type;  /**< Second argument type. */
    };

    /**
     *  Function pointer type.
     *  @tparam U \deduced Return type.
     *  @tparam V1 \deduced Argument type.
     *  @tparam V2 \deduced Argument type.
     *  @tparam V3 \deduced Argument type.
     */
    template <typename U, typename V1, typename V2, typename V3>
    struct FunctionPtrTraits<U (*)(V1, V2, V3)>
    {
        /** Value. */
        enum
        {
            IsFunctionPointer = 1 /**< Function pointer.     */
        };

        /** Value. */ enum
        {
            nArgs = 3 /**< Number of arguments.  */
        };

        typedef U ReturnType; /**< Return type.          */
        typedef V1 Arg1Type;  /**< First argument type.  */
        typedef V2 Arg2Type;  /**< Second argument type. */
        typedef V3 Arg3Type;  /**< Third argument type.  */
    };

    /**
     *  Function pointer type.
     *  @tparam U \deduced Return type.
     *  @tparam V1 \deduced Argument type.
     *  @tparam V2 \deduced Argument type.
     *  @tparam V3 \deduced Argument type.
     *  @tparam V4 \deduced Argument type.
     */
    template <typename U, typename V1, typename V2, typename V3, typename V4>
    struct FunctionPtrTraits<U (*)(V1, V2, V3, V4)>
    {
        /** Value. */
        enum
        {
            IsFunctionPointer = 1 /**< Function pointer.     */
        };

        /** Value. */ enum
        {
            nArgs = 4 /**< Number of arguments.  */
        };

        typedef U ReturnType; /**< Return type.          */
        typedef V1 Arg1Type;  /**< First argument type.  */
        typedef V2 Arg2Type;  /**< Second argument type. */
        typedef V3 Arg3Type;  /**< Third argument type.  */
        typedef V4 Arg4Type;  /**< Fourth argument type. */
    };

    /**
     *  Function pointer type.
     *  @tparam U \deduced Return type.
     *  @tparam V1 \deduced Argument type.
     *  @tparam V2 \deduced Argument type.
     *  @tparam V3 \deduced Argument type.
     *  @tparam V4 \deduced Argument type.
     *  @tparam V5 \deduced Argument type.
     */
    template <typename U, typename V1, typename V2, typename V3, typename V4, typename V5>
    struct FunctionPtrTraits<U (*)(V1, V2, V3, V4, V5)>
    {
        /** Value. */
        enum
        {
            IsFunctionPointer = 1 /**< Function pointer.     */
        };

        /** Value. */ enum
        {
            nArgs = 5 /**< Number of arguments.  */
        };

        typedef U ReturnType; /**< Return type.          */
        typedef V1 Arg1Type;  /**< First argument type.  */
        typedef V2 Arg2Type;  /**< Second argument type. */
        typedef V3 Arg3Type;  /**< Third argument type.  */
        typedef V4 Arg4Type;  /**< Fourth argument type. */
        typedef V5 Arg5Type;  /**< Fifth argument type.  */
    };

    /**
     *  Function pointer type.
     *  @tparam U \deduced Return type.
     *  @tparam V1 \deduced Argument type.
     *  @tparam V2 \deduced Argument type.
     *  @tparam V3 \deduced Argument type.
     *  @tparam V4 \deduced Argument type.
     *  @tparam V5 \deduced Argument type.
     *  @tparam V6 \deduced Argument type.
     */
    template <typename U,
              typename V1,
              typename V2,
              typename V3,
              typename V4,
              typename V5,
              typename V6>
    struct FunctionPtrTraits<U (*)(V1, V2, V3, V4, V5, V6)>
    {
        /** Value. */
        enum
        {
            IsFunctionPointer = 1 /**< Function pointer.     */
        };

        /** Value. */ enum
        {
            nArgs = 6 /**< Number of arguments.  */
        };

        typedef U ReturnType; /**< Return type.          */
        typedef V1 Arg1Type;  /**< First argument type.  */
        typedef V2 Arg2Type;  /**< Second argument type. */
        typedef V3 Arg3Type;  /**< Third argument type.  */
        typedef V4 Arg4Type;  /**< Fourth argument type. */
        typedef V5 Arg5Type;  /**< Fifth argument type.  */
        typedef V6 Arg6Type;  /**< Sixth argument type.  */
    };

    /**
     *  Not a pointer to member type.
     *  @tparam U \deduced Return type.
     */
    template <typename U>
    struct PtrToMemberTraits
    {
        /** Value. */
        enum
        {
            IsPointerToMember = 0 /**< Not a pointer to member.    */
        };
    };

    /**
     *  Pointer to member function.
     *  @tparam U \deduced Return type.
     *  @tparam V \deduced Class type.
     */
    template <typename U, typename V>
    struct PtrToMemberTraits<U (V::*)()>
    {
        /** Value. */
        enum
        {
            IsPointerToMember = 1 /**< Pointer to member function. */
        };

        /** Value. */ enum
        {
            nArgs = 0 /**< Number of arguments.        */
        };

        typedef U ReturnType; /**< Return type.                */
    };

    /**
     *  Pointer to const member function.
     *  @tparam U \deduced Return type.
     *  @tparam V \deduced Class type.
     */
    template <typename U, typename V>
    struct PtrToMemberTraits<U (V::*)() const>
    {
        /** Value. */
        enum
        {
            IsPointerToMember = 1 /**< Pointer to member function. */
        };

        /** Value. */ enum
        {
            nArgs = 0 /**< Number of arguments.        */
        };

        typedef U ReturnType; /**< Return type.                */
    };

    /**
     *  Pointer to member function.
     *  @tparam U \deduced Return type.
     *  @tparam V \deduced Class type.
     *  @tparam W1 \deduced Argument type.
     */
    template <typename U, typename V, typename W1>
    struct PtrToMemberTraits<U (V::*)(W1)>
    {
        /** Value. */
        enum
        {
            IsPointerToMember = 1 /**< Pointer to member function. */
        };

        /** Value. */ enum
        {
            nArgs = 1 /**< Number of arguments.        */
        };

        typedef U ReturnType; /**< Return type.          */
        typedef W1 Arg1Type;  /**< First argument type.  */
    };

    /**
     *  Pointer to const member function.
     *  @tparam U \deduced Return type.
     *  @tparam V \deduced Class type.
     *  @tparam W1 \deduced Argument type.
     */
    template <typename U, typename V, typename W1>
    struct PtrToMemberTraits<U (V::*)(W1) const>
    {
        /** Value. */
        enum
        {
            IsPointerToMember = 1 /**< Pointer to member function. */
        };

        /** Value. */ enum
        {
            nArgs = 1 /**< Number of arguments.        */
        };

        typedef U ReturnType; /**< Return type.          */
        typedef W1 Arg1Type;  /**< First argument type.  */
    };

    /**
     *  Pointer to member function.
     *  @tparam U \deduced Return type.
     *  @tparam V \deduced Class type.
     *  @tparam W1 \deduced Argument type.
     *  @tparam W2 \deduced Argument type.
     */
    template <typename U, typename V, typename W1, typename W2>
    struct PtrToMemberTraits<U (V::*)(W1, W2)>
    {
        /** Value. */
        enum
        {
            IsPointerToMember = 1 /**< Pointer to member function. */
        };

        /** Value. */ enum
        {
            nArgs = 2 /**< Number of arguments.        */
        };

        typedef U ReturnType; /**< Return type.          */
        typedef W1 Arg1Type;  /**< First argument type.  */
        typedef W2 Arg2Type;  /**< Second argument type. */
    };

    /**
     *  Pointer to const member function.
     *  @tparam U \deduced Return type.
     *  @tparam V \deduced Class type.
     *  @tparam W1 \deduced Argument type.
     *  @tparam W2 \deduced Argument type.
     */
    template <typename U, typename V, typename W1, typename W2>
    struct PtrToMemberTraits<U (V::*)(W1, W2) const>
    {
        /** Value. */
        enum
        {
            IsPointerToMember = 1 /**< Pointer to member function. */
        };

        /** Value. */ enum
        {
            nArgs = 2 /**< Number of arguments.        */
        };

        typedef U ReturnType; /**< Return type.          */
        typedef W1 Arg1Type;  /**< First argument type.  */
        typedef W2 Arg2Type;  /**< Second argument type. */
    };

    /**
     *  Pointer to member function.
     *  @tparam U \deduced Return type.
     *  @tparam V \deduced Class type.
     *  @tparam W1 \deduced Argument type.
     *  @tparam W2 \deduced Argument type.
     *  @tparam W3 \deduced Argument type.
     */
    template <typename U, typename V, typename W1, typename W2, typename W3>
    struct PtrToMemberTraits<U (V::*)(W1, W2, W3)>
    {
        /** Value. */
        enum
        {
            IsPointerToMember = 1 /**< Pointer to member function. */
        };

        /** Value. */ enum
        {
            nArgs = 3 /**< Number of arguments.        */
        };

        typedef U ReturnType; /**< Return type.          */
        typedef W1 Arg1Type;  /**< First argument type.  */
        typedef W2 Arg2Type;  /**< Second argument type. */
        typedef W3 Arg3Type;  /**< Third argument type.  */
    };

    /**
     *  Pointer to const member function.
     *  @tparam U \deduced Return type.
     *  @tparam V \deduced Class type.
     *  @tparam W1 \deduced Argument type.
     *  @tparam W2 \deduced Argument type.
     *  @tparam W3 \deduced Argument type.
     */
    template <typename U, typename V, typename W1, typename W2, typename W3>
    struct PtrToMemberTraits<U (V::*)(W1, W2, W3) const>
    {
        /** Value. */
        enum
        {
            IsPointerToMember = 1 /**< Pointer to member function. */
        };

        /** Value. */ enum
        {
            nArgs = 3 /**< Number of arguments.        */
        };

        typedef U ReturnType; /**< Return type.          */
        typedef W1 Arg1Type;  /**< First argument type.  */
        typedef W2 Arg2Type;  /**< Second argument type. */
        typedef W3 Arg3Type;  /**< Third argument type.  */
    };

    /**
     *  Pointer to member function.
     *  @tparam U \deduced Return type.
     *  @tparam V \deduced Class type.
     *  @tparam W1 \deduced Argument type.
     *  @tparam W2 \deduced Argument type.
     *  @tparam W3 \deduced Argument type.
     *  @tparam W4 \deduced Argument type.
     */
    template <typename U, typename V, typename W1, typename W2, typename W3, typename W4>
    struct PtrToMemberTraits<U (V::*)(W1, W2, W3, W4)>
    {
        /** Value. */
        enum
        {
            IsPointerToMember = 1 /**< Pointer to member function. */
        };

        /** Value. */ enum
        {
            nArgs = 4 /**< Number of arguments.        */
        };

        typedef U ReturnType; /**< Return type.          */
        typedef W1 Arg1Type;  /**< First argument type.  */
        typedef W2 Arg2Type;  /**< Second argument type. */
        typedef W3 Arg3Type;  /**< Third argument type.  */
        typedef W4 Arg4Type;  /**< Fourth argument type. */
    };

    /**
     *  Pointer to const member function.
     *  @tparam U \deduced Return type.
     *  @tparam V \deduced Class type.
     *  @tparam W1 \deduced Argument type.
     *  @tparam W2 \deduced Argument type.
     *  @tparam W3 \deduced Argument type.
     *  @tparam W4 \deduced Argument type.
     */
    template <typename U, typename V, typename W1, typename W2, typename W3, typename W4>
    struct PtrToMemberTraits<U (V::*)(W1, W2, W3, W4) const>
    {
        /** Value. */
        enum
        {
            IsPointerToMember = 1 /**< Pointer to member function. */
        };

        /** Value. */ enum
        {
            nArgs = 4 /**< Number of arguments.        */
        };

        typedef U ReturnType; /**< Return type.          */
        typedef W1 Arg1Type;  /**< First argument type.  */
        typedef W2 Arg2Type;  /**< Second argument type. */
        typedef W3 Arg3Type;  /**< Third argument type.  */
        typedef W4 Arg4Type;  /**< Fourth argument type. */
    };

    /**
     *  Pointer to member function.
     *  @tparam U \deduced Return type.
     *  @tparam V \deduced Class type.
     *  @tparam W1 \deduced Argument type.
     *  @tparam W2 \deduced Argument type.
     *  @tparam W3 \deduced Argument type.
     *  @tparam W4 \deduced Argument type.
     *  @tparam W5 \deduced Argument type.
     */
    template <typename U,
              typename V,
              typename W1,
              typename W2,
              typename W3,
              typename W4,
              typename W5>
    struct PtrToMemberTraits<U (V::*)(W1, W2, W3, W4, W5)>
    {
        /** Value. */
        enum
        {
            IsPointerToMember = 1 /**< Pointer to member function. */
        };

        /** Value. */ enum
        {
            nArgs = 5 /**< Number of arguments.        */
        };

        typedef U ReturnType; /**< Return type.          */
        typedef W1 Arg1Type;  /**< First argument type.  */
        typedef W2 Arg2Type;  /**< Second argument type. */
        typedef W3 Arg3Type;  /**< Third argument type.  */
        typedef W4 Arg4Type;  /**< Fourth argument type. */
        typedef W5 Arg5Type;  /**< Fifth argument type.  */
    };

    /**
     *  Pointer to const member function.
     *  @tparam U \deduced Return type.
     *  @tparam V \deduced Class type.
     *  @tparam W1 \deduced Argument type.
     *  @tparam W2 \deduced Argument type.
     *  @tparam W3 \deduced Argument type.
     *  @tparam W4 \deduced Argument type.
     *  @tparam W5 \deduced Argument type.
     */
    template <typename U,
              typename V,
              typename W1,
              typename W2,
              typename W3,
              typename W4,
              typename W5>
    struct PtrToMemberTraits<U (V::*)(W1, W2, W3, W4, W5) const>
    {
        /** Value. */
        enum
        {
            IsPointerToMember = 1 /**< Pointer to member function. */
        };

        /** Value. */ enum
        {
            nArgs = 5 /**< Number of arguments.        */
        };

        typedef U ReturnType; /**< Return type.          */
        typedef W1 Arg1Type;  /**< First argument type.  */
        typedef W2 Arg2Type;  /**< Second argument type. */
        typedef W3 Arg3Type;  /**< Third argument type.  */
        typedef W4 Arg4Type;  /**< Fourth argument type. */
        typedef W5 Arg5Type;  /**< Fifth argument type.  */
    };

    /**
     *  Pointer to member function.
     *  @tparam U \deduced Return type.
     *  @tparam V \deduced Class type.
     *  @tparam W1 \deduced Argument type.
     *  @tparam W2 \deduced Argument type.
     *  @tparam W3 \deduced Argument type.
     *  @tparam W4 \deduced Argument type.
     *  @tparam W5 \deduced Argument type.
     *  @tparam W6 \deduced Argument type.
     */
    template <typename U,
              typename V,
              typename W1,
              typename W2,
              typename W3,
              typename W4,
              typename W5,
              typename W6>
    struct PtrToMemberTraits<U (V::*)(W1, W2, W3, W4, W5, W6)>
    {
        /** Value. */
        enum
        {
            IsPointerToMember = 1 /**< Pointer to member function. */
        };

        /** Value. */ enum
        {
            nArgs = 6 /**< Number of arguments.        */
        };

        typedef U ReturnType; /**< Return type.          */
        typedef W1 Arg1Type;  /**< First argument type.  */
        typedef W2 Arg2Type;  /**< Second argument type. */
        typedef W3 Arg3Type;  /**< Third argument type.  */
        typedef W4 Arg4Type;  /**< Fourth argument type. */
        typedef W5 Arg5Type;  /**< Fifth argument type.  */
        typedef W6 Arg6Type;  /**< Sixth argument type.  */
    };

    /**
     *  Pointer to const member function.
     *  @tparam U \deduced Return type.
     *  @tparam V \deduced Class type.
     *  @tparam W1 \deduced Argument type.
     *  @tparam W2 \deduced Argument type.
     *  @tparam W3 \deduced Argument type.
     *  @tparam W4 \deduced Argument type.
     *  @tparam W5 \deduced Argument type.
     *  @tparam W6 \deduced Argument type.
     */
    template <typename U,
              typename V,
              typename W1,
              typename W2,
              typename W3,
              typename W4,
              typename W5,
              typename W6>
    struct PtrToMemberTraits<U (V::*)(W1, W2, W3, W4, W5, W6) const>
    {
        /** Value. */
        enum
        {
            IsPointerToMember = 1 /**< Pointer to member function. */
        };

        /** Value. */ enum
        {
            nArgs = 6 /**< Number of arguments.        */
        };

        typedef U ReturnType; /**< Return type.          */
        typedef W1 Arg1Type;  /**< First argument type.  */
        typedef W2 Arg2Type;  /**< Second argument type. */
        typedef W3 Arg3Type;  /**< Third argument type.  */
        typedef W4 Arg4Type;  /**< Fourth argument type. */
        typedef W5 Arg5Type;  /**< Fifth argument type.  */
        typedef W6 Arg6Type;  /**< Sixth argument type.  */
    };

  public:
    /** Not a const type. */
    typedef typename UnConst<T>::Result NonConstType;
    /** Referenced type. */
    typedef typename ReferenceTraits<T>::ReferencedType ReferencedType;
    /** Pointee type. */
    typedef typename PointerTraits<T>::PointeeType PointeeType;
    /** Base type, after removing \c &, \c * and \c const. */
    typedef typename Base<T>::Type BaseType;
    /** Ptr base type. */
    typedef typename PtrBase<T>::Type PtrBaseType;

    /** Predicates. */
    enum
    {
        /** Pointer to member predicate. */
        IsPointerToMember = PtrToMemberTraits<T>::IsPointerToMember,
        /** Pointer predicate. */
        IsPointer = PointerTraits<T>::IsPointer,
        /** Ptr predicate. */
        IsPtr = PointerTraits<T>::IsPtr,
        /** Reference predicate. */
        IsReference = ReferenceTraits<T>::IsReference,
        /** Function pointer predicate. */
        IsFunctionPointer = FunctionPtrTraits<T>::IsFunctionPointer
    };

    /** Pointer to member traits type. */
    typedef PtrToMemberTraits<T> PointerToMemberTraits;
    /** Function pointer traits. */
    typedef FunctionPtrTraits<T> FunctionPointerTraits;
};

} // namespace ns3

#endif /* TYPE_TRAITS_H */
