ulib/3party/nonstd/any.h

//
// Copyright (c) 2016-2018 Martin Moene
//
// https://github.com/martinmoene/any-lite
//
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

#pragma once

#ifndef NONSTD_ANY_LITE_HPP
#define NONSTD_ANY_LITE_HPP

#define any_lite_MAJOR 0
#define any_lite_MINOR 4
#define any_lite_PATCH 0

#define any_lite_VERSION                                                       \
    any_STRINGIFY(any_lite_MAJOR) "." any_STRINGIFY(                           \
        any_lite_MINOR) "." any_STRINGIFY(any_lite_PATCH)

#define any_STRINGIFY(x) any_STRINGIFY_(x)
#define any_STRINGIFY_(x) #x

// any-lite configuration:

#define any_ANY_DEFAULT 0
#define any_ANY_NONSTD 1
#define any_ANY_STD 2

// tweak header support:

#ifdef __has_include
#if __has_include(<nonstd/any.tweak.hpp>)
#include <nonstd/any.tweak.hpp>
#endif
#define any_HAVE_TWEAK_HEADER 1
#else
#define any_HAVE_TWEAK_HEADER 0
//# pragma message("any.hpp: Note: Tweak header not supported.")
#endif

// any selection and configuration:

#if !defined(any_CONFIG_SELECT_ANY)
#define any_CONFIG_SELECT_ANY (any_HAVE_STD_ANY ? any_ANY_STD : any_ANY_NONSTD)
#endif

// Control presence of exception handling (try and auto discover):

#ifndef any_CONFIG_NO_EXCEPTIONS
#if defined(_MSC_VER)
#include <cstddef>// for _HAS_EXCEPTIONS
#endif
#if defined(__cpp_exceptions) || defined(__EXCEPTIONS) || (_HAS_EXCEPTIONS)
#define any_CONFIG_NO_EXCEPTIONS 0
#else
#define any_CONFIG_NO_EXCEPTIONS 1
#endif
#endif

// C++ language version detection (C++23 is speculative):
// Note: VC14.0/1900 (VS2015) lacks too much from C++14.

#ifndef any_CPLUSPLUS
#if defined(_MSVC_LANG) && !defined(__clang__)
#define any_CPLUSPLUS (_MSC_VER == 1900 ? 201103L : _MSVC_LANG)
#else
#define any_CPLUSPLUS __cplusplus
#endif
#endif

#define any_CPP98_OR_GREATER (any_CPLUSPLUS >= 199711L)
#define any_CPP11_OR_GREATER (any_CPLUSPLUS >= 201103L)
#define any_CPP14_OR_GREATER (any_CPLUSPLUS >= 201402L)
#define any_CPP17_OR_GREATER (any_CPLUSPLUS >= 201703L)
#define any_CPP20_OR_GREATER (any_CPLUSPLUS >= 202002L)
#define any_CPP23_OR_GREATER (any_CPLUSPLUS >= 202300L)

// Use C++17 std::any if available and requested:

#if any_CPP17_OR_GREATER && defined(__has_include)
#if __has_include(<any> )
#define any_HAVE_STD_ANY 1
#else
#define any_HAVE_STD_ANY 0
#endif
#else
#define any_HAVE_STD_ANY 0
#endif

#define any_USES_STD_ANY                                                       \
    ((any_CONFIG_SELECT_ANY == any_ANY_STD)                                    \
     || ((any_CONFIG_SELECT_ANY == any_ANY_DEFAULT) && any_HAVE_STD_ANY))

//
// in_place: code duplicated in any-lite, expected-lite, optional-lite, value-ptr-lite, variant-lite:
//

#ifndef nonstd_lite_HAVE_IN_PLACE_TYPES
#define nonstd_lite_HAVE_IN_PLACE_TYPES 1

// C++17 std::in_place in <utility>:

#if any_CPP17_OR_GREATER

#include <utility>

namespace nonstd {

using std::in_place;
using std::in_place_index;
using std::in_place_index_t;
using std::in_place_t;
using std::in_place_type;
using std::in_place_type_t;

#define nonstd_lite_in_place_t(T) std::in_place_t
#define nonstd_lite_in_place_type_t(T) std::in_place_type_t<T>
#define nonstd_lite_in_place_index_t(K) std::in_place_index_t<K>

#define nonstd_lite_in_place(T)                                                \
    std::in_place_t {}
#define nonstd_lite_in_place_type(T)                                           \
    std::in_place_type_t<T> {}
#define nonstd_lite_in_place_index(K)                                          \
    std::in_place_index_t<K> {}

}// namespace nonstd

#else// any_CPP17_OR_GREATER

#include <cstddef>

namespace nonstd {
namespace detail {

template<class T>
struct in_place_type_tag {};

template<std::size_t K>
struct in_place_index_tag {};

}// namespace detail

struct in_place_t {};

template<class T>
inline in_place_t
in_place(detail::in_place_type_tag<T> = detail::in_place_type_tag<T>())
{
    return in_place_t();
}

template<std::size_t K>
inline in_place_t
in_place(detail::in_place_index_tag<K> = detail::in_place_index_tag<K>())
{
    return in_place_t();
}

template<class T>
inline in_place_t
in_place_type(detail::in_place_type_tag<T> = detail::in_place_type_tag<T>())
{
    return in_place_t();
}

template<std::size_t K>
inline in_place_t
in_place_index(detail::in_place_index_tag<K> = detail::in_place_index_tag<K>())
{
    return in_place_t();
}

// mimic templated typedef:

#define nonstd_lite_in_place_t(T)                                              \
    nonstd::in_place_t (&)(nonstd::detail::in_place_type_tag<T>)
#define nonstd_lite_in_place_type_t(T)                                         \
    nonstd::in_place_t (&)(nonstd::detail::in_place_type_tag<T>)
#define nonstd_lite_in_place_index_t(K)                                        \
    nonstd::in_place_t (&)(nonstd::detail::in_place_index_tag<K>)

#define nonstd_lite_in_place(T) nonstd::in_place_type<T>
#define nonstd_lite_in_place_type(T) nonstd::in_place_type<T>
#define nonstd_lite_in_place_index(K) nonstd::in_place_index<K>

}// namespace nonstd

#endif// any_CPP17_OR_GREATER
#endif// nonstd_lite_HAVE_IN_PLACE_TYPES

//
// Using std::any:
//

#if any_USES_STD_ANY

#include <any>
#include <utility>

namespace nonstd {

using std::any;
using std::any_cast;
using std::bad_any_cast;
using std::make_any;
using std::swap;
}// namespace nonstd

#else// any_USES_STD_ANY

#if !any_CPP11_OR_GREATER
#include <algorithm>// std::swap()
#endif

#include <utility>

// Compiler versions:
//
// MSVC++  6.0  _MSC_VER == 1200  any_COMPILER_MSVC_VERSION ==  60  (Visual Studio 6.0)
// MSVC++  7.0  _MSC_VER == 1300  any_COMPILER_MSVC_VERSION ==  70  (Visual Studio .NET 2002)
// MSVC++  7.1  _MSC_VER == 1310  any_COMPILER_MSVC_VERSION ==  71  (Visual Studio .NET 2003)
// MSVC++  8.0  _MSC_VER == 1400  any_COMPILER_MSVC_VERSION ==  80  (Visual Studio 2005)
// MSVC++  9.0  _MSC_VER == 1500  any_COMPILER_MSVC_VERSION ==  90  (Visual Studio 2008)
// MSVC++ 10.0  _MSC_VER == 1600  any_COMPILER_MSVC_VERSION == 100  (Visual Studio 2010)
// MSVC++ 11.0  _MSC_VER == 1700  any_COMPILER_MSVC_VERSION == 110  (Visual Studio 2012)
// MSVC++ 12.0  _MSC_VER == 1800  any_COMPILER_MSVC_VERSION == 120  (Visual Studio 2013)
// MSVC++ 14.0  _MSC_VER == 1900  any_COMPILER_MSVC_VERSION == 140  (Visual Studio 2015)
// MSVC++ 14.1  _MSC_VER >= 1910  any_COMPILER_MSVC_VERSION == 141  (Visual Studio 2017)
// MSVC++ 14.2  _MSC_VER >= 1920  any_COMPILER_MSVC_VERSION == 142  (Visual Studio 2019)

#if defined(_MSC_VER) && !defined(__clang__)
#define any_COMPILER_MSVC_VER (_MSC_VER)
#define any_COMPILER_MSVC_VERSION (_MSC_VER / 10 - 10 * (5 + (_MSC_VER < 1900)))
#else
#define any_COMPILER_MSVC_VER 0
#define any_COMPILER_MSVC_VERSION 0
#endif

#define any_COMPILER_VERSION(major, minor, patch)                              \
    (10 * (10 * (major) + (minor)) + (patch))

#if defined(__clang__)
#define any_COMPILER_CLANG_VERSION                                             \
    any_COMPILER_VERSION(__clang_major__, __clang_minor__, __clang_patchlevel__)
#else
#define any_COMPILER_CLANG_VERSION 0
#endif

#if defined(__GNUC__) && !defined(__clang__)
#define any_COMPILER_GNUC_VERSION                                              \
    any_COMPILER_VERSION(__GNUC__, __GNUC_MINOR__, __GNUC_PATCHLEVEL__)
#else
#define any_COMPILER_GNUC_VERSION 0
#endif

// half-open range [lo..hi):
//#define any_BETWEEN( v, lo, hi ) ( (lo) <= (v) && (v) < (hi) )

// Presence of language and library features:

#define any_HAVE(feature) (any_HAVE_##feature)

#ifdef _HAS_CPP0X
#define any_HAS_CPP0X _HAS_CPP0X
#else
#define any_HAS_CPP0X 0
#endif

#define any_CPP11_90 (any_CPP11_OR_GREATER || any_COMPILER_MSVC_VER >= 1500)
#define any_CPP11_100 (any_CPP11_OR_GREATER || any_COMPILER_MSVC_VER >= 1600)
#define any_CPP11_120 (any_CPP11_OR_GREATER || any_COMPILER_MSVC_VER >= 1800)
#define any_CPP11_140 (any_CPP11_OR_GREATER || any_COMPILER_MSVC_VER >= 1900)

#define any_CPP14_000 (any_CPP14_OR_GREATER)
#define any_CPP17_000 (any_CPP17_OR_GREATER)

// Presence of C++11 language features:

#define any_HAVE_CONSTEXPR_11 any_CPP11_140
#define any_HAVE_DEFAULT_FUNCTION_TEMPLATE_ARG any_CPP11_120
#define any_HAVE_INITIALIZER_LIST any_CPP11_120
#define any_HAVE_NOEXCEPT any_CPP11_140
#define any_HAVE_NULLPTR any_CPP11_100
#define any_HAVE_TYPE_TRAITS any_CPP11_90
#define any_HAVE_STATIC_ASSERT any_CPP11_100
#define any_HAVE_ADD_CONST any_CPP11_90
#define any_HAVE_OVERRIDE any_CPP11_90
#define any_HAVE_REMOVE_REFERENCE any_CPP11_90

#define any_HAVE_TR1_ADD_CONST (!!any_COMPILER_GNUC_VERSION)
#define any_HAVE_TR1_REMOVE_REFERENCE (!!any_COMPILER_GNUC_VERSION)
#define any_HAVE_TR1_TYPE_TRAITS (!!any_COMPILER_GNUC_VERSION)

// Presence of C++14 language features:

#define any_HAVE_CONSTEXPR_14 any_CPP14_000

// Presence of C++17 language features:

#define any_HAVE_NODISCARD any_CPP17_000

// Presence of C++ language features:

#if any_HAVE_CONSTEXPR_11
#define any_constexpr constexpr
#else
#define any_constexpr /*constexpr*/
#endif

#if any_HAVE_CONSTEXPR_14
#define any_constexpr14 constexpr
#else
#define any_constexpr14 /*constexpr*/
#endif

#if any_HAVE_NOEXCEPT
#define any_noexcept noexcept
#else
#define any_noexcept /*noexcept*/
#endif

#if any_HAVE_NULLPTR
#define any_nullptr nullptr
#else
#define any_nullptr NULL
#endif

#if any_HAVE_NODISCARD
#define any_nodiscard [[nodiscard]]
#else
#define any_nodiscard /*[[nodiscard]]*/
#endif

#if any_HAVE_OVERRIDE
#define any_override override
#else
#define any_override /*override*/
#endif

// additional includes:

#if any_CONFIG_NO_EXCEPTIONS
#include <cassert>
#else
#include <typeinfo>
#endif

#if !any_HAVE_NULLPTR
#include <cstddef>
#endif

#if any_HAVE_INITIALIZER_LIST
#include <initializer_list>
#endif

#if any_HAVE_TYPE_TRAITS
#include <type_traits>
#elif any_HAVE_TR1_TYPE_TRAITS
#include <tr1/type_traits>
#endif

// Method enabling

#if any_CPP11_OR_GREATER

#define any_REQUIRES_0(...)                                                    \
    template<bool B = (__VA_ARGS__), typename std::enable_if<B, int>::type = 0>

#define any_REQUIRES_T(...)                                                    \
    , typename std::enable_if<(__VA_ARGS__), int>::type = 0

#define any_REQUIRES_R(R, ...) typename std::enable_if<__VA_ARGS__, R>::type

#define any_REQUIRES_A(...)                                                    \
    , typename std::enable_if<__VA_ARGS__, void *>::type = nullptr

#endif

//
// any:
//

namespace nonstd {
namespace any_lite {

// C++11 emulation:

namespace std11 {

#if any_HAVE_ADD_CONST

using std::add_const;

#elif any_HAVE_TR1_ADD_CONST

using std::tr1::add_const;

#else

template<class T>
struct add_const {
    typedef const T type;
};

#endif// any_HAVE_ADD_CONST

#if any_HAVE_REMOVE_REFERENCE

using std::remove_reference;

#elif any_HAVE_TR1_REMOVE_REFERENCE

using std::tr1::remove_reference;

#else

template<class T>
struct remove_reference {
    typedef T type;
};

template<class T>
struct remove_reference<T &> {
    typedef T type;
};

#endif// any_HAVE_REMOVE_REFERENCE

}// namespace std11

namespace detail {

// for any_REQUIRES_T

/*enum*/ class enabler {};

}// namespace detail

#if !any_CONFIG_NO_EXCEPTIONS

class bad_any_cast : public std::bad_cast {
public:
#if any_CPP11_OR_GREATER
    virtual const char *what() const any_noexcept any_override
#else
    virtual const char *what() const throw()
#endif
    {
        return "any-lite: bad any_cast";
    }
};

#endif// any_CONFIG_NO_EXCEPTIONS

class any {
public:
    any_constexpr any() any_noexcept : content(any_nullptr) {}

    any(any const &other)
        : content(other.content ? other.content->clone() : any_nullptr)
    {}

#if any_CPP11_OR_GREATER

    any(any &&other) any_noexcept : content(std::move(other.content))
    {
        other.content = any_nullptr;
    }

    template<class ValueType,
             class T = typename std::decay<ValueType>::type any_REQUIRES_T(
                 !std::is_same<T, any>::value)>
    any(ValueType &&value) any_noexcept
        : content(new holder<T>(std::forward<ValueType>(value)))
    {}

    template<class T,
             class... Args any_REQUIRES_T(
                 std::is_constructible<T, Args &&...>::value)>
    explicit any(nonstd_lite_in_place_type_t(T), Args &&...args)
        : content(new holder<T>(T(std::forward<Args>(args)...)))
    {}

    template<class T,
             class U,
             class... Args any_REQUIRES_T(
                 std::is_constructible<T,
                                       std::initializer_list<U> &,
                                       Args &&...>::value)>
    explicit any(nonstd_lite_in_place_type_t(T),
                 std::initializer_list<U> il,
                 Args &&...args)
        : content(new holder<T>(T(il, std::forward<Args>(args)...)))
    {}

#else

    template<class ValueType>
    any(ValueType const &value) : content(new holder<ValueType>(value))
    {}

#endif// any_CPP11_OR_GREATER

    ~any() { reset(); }

    any &operator=(any const &other)
    {
        any(other).swap(*this);
        return *this;
    }

#if any_CPP11_OR_GREATER

    any &operator=(any &&other) any_noexcept
    {
        any(std::move(other)).swap(*this);
        return *this;
    }

    template<class ValueType,
             class T = typename std::decay<ValueType>::type any_REQUIRES_T(
                 !std::is_same<T, any>::value)>
    any &operator=(T &&value)
    {
        any(std::move(value)).swap(*this);
        return *this;
    }

    template<class T, class... Args>
    void emplace(Args &&...args)
    {
        any(T(std::forward<Args>(args)...)).swap(*this);
    }

    template<class T,
             class U,
             class... Args any_REQUIRES_T(
                 std::is_constructible<T,
                                       std::initializer_list<U> &,
                                       Args &&...>::value)>
    void emplace(std::initializer_list<U> il, Args &&...args)
    {
        any(T(il, std::forward<Args>(args)...)).swap(*this);
    }

#else

    template<class ValueType>
    any &operator=(ValueType const &value)
    {
        any(value).swap(*this);
        return *this;
    }

#endif// any_CPP11_OR_GREATER

    void reset() any_noexcept
    {
        delete content;
        content = any_nullptr;
    }

    void swap(any &other) any_noexcept { std::swap(content, other.content); }

    bool has_value() const any_noexcept { return content != any_nullptr; }

    const std::type_info &type() const any_noexcept
    {
        return has_value() ? content->type() : typeid(void);
    }

    //
    // non-standard:
    //

    template<class ValueType>
    const ValueType *to_ptr() const
    {
        return &(static_cast<holder<ValueType> *>(content)->held);
    }

    template<class ValueType>
    ValueType *to_ptr()
    {
        return &(static_cast<holder<ValueType> *>(content)->held);
    }

private:
    class placeholder {
    public:
        virtual ~placeholder() {}

        virtual std::type_info const &type() const = 0;

        virtual placeholder *clone() const = 0;
    };

    template<typename ValueType>
    class holder : public placeholder {
    public:
        holder(ValueType const &value) : held(value) {}

#if any_CPP11_OR_GREATER
        holder(ValueType &&value) : held(std::move(value)) {}
#endif

        virtual std::type_info const &type() const any_override
        {
            return typeid(ValueType);
        }

        virtual placeholder *clone() const any_override
        {
            return new holder(held);
        }

        ValueType held;
    };

    placeholder *content;
};

inline void
swap(any &x, any &y) any_noexcept
{
    x.swap(y);
}

#if any_CPP11_OR_GREATER

template<class T, class... Args>
inline any
make_any(Args &&...args)
{
    return any(nonstd_lite_in_place_type(T), std::forward<Args>(args)...);
}

template<class T, class U, class... Args>
inline any
make_any(std::initializer_list<U> il, Args &&...args)
{
    return any(nonstd_lite_in_place_type(T), il, std::forward<Args>(args)...);
}

#endif// any_CPP11_OR_GREATER

template<class ValueType
#if any_HAVE_DEFAULT_FUNCTION_TEMPLATE_ARG
         //  any_REQUIRES_T(...) Allow for VC120 (VS2013):
         ,
         typename = typename std::enable_if<
             (std::is_reference<ValueType>::value
              || std::is_copy_constructible<ValueType>::value),
             nonstd::any_lite::detail::enabler>::type
#endif
         >
any_nodiscard inline ValueType
any_cast(any const &operand)
{
    const ValueType *result = any_cast<typename std11::add_const<
        typename std11::remove_reference<ValueType>::type>::type>(&operand);

#if any_CONFIG_NO_EXCEPTIONS
    assert(result);
#else
    if (!result) { throw bad_any_cast(); }
#endif

    return *result;
}

template<class ValueType
#if any_HAVE_DEFAULT_FUNCTION_TEMPLATE_ARG
         //  any_REQUIRES_T(...) Allow for VC120 (VS2013):
         ,
         typename = typename std::enable_if<
             (std::is_reference<ValueType>::value
              || std::is_copy_constructible<ValueType>::value),
             nonstd::any_lite::detail::enabler>::type
#endif
         >
any_nodiscard inline ValueType
any_cast(any &operand)
{
    const ValueType *result =
        any_cast<typename std11::remove_reference<ValueType>::type>(&operand);

#if any_CONFIG_NO_EXCEPTIONS
    assert(result);
#else
    if (!result) { throw bad_any_cast(); }
#endif

    return *result;
}

#if any_CPP11_OR_GREATER

template<class ValueType
#if any_HAVE_DEFAULT_FUNCTION_TEMPLATE_ARG
             any_REQUIRES_T(std::is_reference<ValueType>::value
                            || std::is_copy_constructible<ValueType>::value)
#endif
         >
any_nodiscard inline ValueType
any_cast(any &&operand)
{
    const ValueType *result =
        any_cast<typename std11::remove_reference<ValueType>::type>(&operand);

#if any_CONFIG_NO_EXCEPTIONS
    assert(result);
#else
    if (!result) { throw bad_any_cast(); }
#endif

    return *result;
}

#endif// any_CPP11_OR_GREATER

template<class ValueType>
any_nodiscard inline ValueType const *
any_cast(any const *operand) any_noexcept
{
    return operand != any_nullptr && operand->type() == typeid(ValueType)
        ? operand->to_ptr<ValueType>()
        : any_nullptr;
}

template<class ValueType>
any_nodiscard inline ValueType *
any_cast(any *operand) any_noexcept
{
    return operand != any_nullptr && operand->type() == typeid(ValueType)
        ? operand->to_ptr<ValueType>()
        : any_nullptr;
}

}// namespace any_lite

using namespace any_lite;

}// namespace nonstd

namespace ulib {
using namespace nonstd::any_lite;
}

#endif// any_USES_STD_ANY

#endif// NONSTD_ANY_LITE_HPP