view.hpp

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// Copyright 2009-present MongoDB, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
 
#pragma once
 
#include <bsoncxx/types/bson_value/view-fwd.hpp> // IWYU pragma: export
 
//
 
#include <bsoncxx/v1/types/view.hpp> // IWYU pragma: export
 
#include <cstddef>
#include <cstdint> // IWYU pragma: keep: backward compatibility, to be removed.
#include <type_traits>
 
#include <bsoncxx/document/element-fwd.hpp> // IWYU pragma: keep: backward compatibility, to be removed.
#include <bsoncxx/types/bson_value/value-fwd.hpp>
 
#include <bsoncxx/stdx/type_traits.hpp>
#include <bsoncxx/types.hpp>
 
#include <bsoncxx/config/prelude.hpp>
 
namespace bsoncxx {
namespace detail {
 
template <typename T>
using is_bson_view_compatible = detail::conjunction<
    std::is_constructible<v_noabi::types::bson_value::view, T>,
    detail::negation<detail::disjunction<
        detail::is_alike<T, v_noabi::types::bson_value::view>,
        detail::is_alike<T, v_noabi::types::bson_value::value>>>>;
 
} // namespace detail
} // namespace bsoncxx
 
namespace bsoncxx {
namespace v_noabi {
namespace types {
namespace bson_value {

class view {
   private:
    v_noabi::type _id;
 
#pragma push_macro("X")
#undef X
#define X(_name, _value) b_##_name _b_##_name;
 
    union {
        BSONCXX_V1_TYPES_XMACRO(X)
    };
#pragma pop_macro("X")
 
   public:
    view() noexcept : _id{v_noabi::type::k_null}, _b_null{} {}

    /* explicit(false) */ view(v1::types::view const& v) : _id{from_v1(v.type_id())} {
#pragma push_macro("X")
#undef X
#define X(_name, _value)                       \
    case v_noabi::type::k_##_name:             \
        _b_##_name = from_v1(v.get_##_name()); \
        break;
 
        switch (_id) { BSONCXX_V1_TYPES_XMACRO(X) }
#pragma pop_macro("X")
    }
 
#pragma push_macro("X")
#undef X
 
// For backward compatibility, the `from_v1(to_v1(v))` round-trip ensures empty string-like BSON type values are always
// represented as not-null empty strings.
#define X(_name, _value) \
    explicit view(v_noabi::types::b_##_name v) noexcept : _id{v.type_id}, _b_##_name{from_v1(to_v1(v))} {}

    BSONCXX_V1_TYPES_XMACRO(X)
#pragma pop_macro("X")

    explicit operator v1::types::view() const {
#pragma push_macro("X")
#undef X
#define X(_name, _value)           \
    case v_noabi::type::k_##_name: \
        return {to_v1(_b_##_name)};
 
        switch (_id) {
            BSONCXX_V1_TYPES_XMACRO(X)
 
            default:
                return {}; // Unreachable.
        }
#pragma pop_macro("X")
    }

    v_noabi::type type() const {
        return _id;
    }

    v_noabi::type type_id() const {
        return _id;
    }
 
#pragma push_macro("X")
#undef X
#define X(_name, _value) BSONCXX_ABI_EXPORT_CDECL_UNSTABLE(v_noabi::types::b_##_name const&) get_##_name() const;

    BSONCXX_V1_TYPES_XMACRO(X)
#pragma pop_macro("X")

    friend BSONCXX_ABI_EXPORT_CDECL_UNSTABLE(bool) operator==(view const& lhs, view const& rhs);
 
    friend bool operator!=(view const& lhs, view const& rhs) {
        return !(lhs == rhs);
    }

};


template <typename T>
detail::requires_t<bool, detail::is_bson_view_compatible<T>> operator==(view const& lhs, T&& rhs) {
    return lhs == view{std::forward<T>(rhs)};
}

template <typename T>
detail::requires_t<bool, detail::is_bson_view_compatible<T>> operator==(T&& lhs, view const& rhs) {
    return view{std::forward<T>(lhs)} == rhs;
}

template <typename T>
detail::requires_t<bool, detail::is_bson_view_compatible<T>> operator!=(view const& lhs, T&& rhs) {
    return lhs != view{std::forward<T>(rhs)};
}

template <typename T>
detail::requires_t<bool, detail::is_bson_view_compatible<T>> operator!=(T&& lhs, view const& rhs) {
    return view{std::forward<T>(lhs)} != rhs;
}

 
} // namespace bson_value
} // namespace types
} // namespace v_noabi
} // namespace bsoncxx
 
namespace bsoncxx {
namespace v_noabi {

inline v_noabi::types::bson_value::view from_v1(v1::types::view const& v) {
    return {v};
}

inline v1::types::view to_v1(v_noabi::types::bson_value::view const& v) {
    return v1::types::view{v};
}
 
} // namespace v_noabi
} // namespace bsoncxx
 
namespace bsoncxx {
namespace types {
namespace bson_value {
 
using v_noabi::types::bson_value::operator==;
using v_noabi::types::bson_value::operator!=;
 
} // namespace bson_value
} // namespace types
} // namespace bsoncxx
 
#include <bsoncxx/config/postlude.hpp>