view.hpp

// Copyright 2020 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 <cstddef>
#include <cstdint>
#include <type_traits>
 
#include <bsoncxx/types.hpp>
 
#include <bsoncxx/config/prelude.hpp>
 
namespace bsoncxx {
BSONCXX_INLINE_NAMESPACE_BEGIN
 
namespace document {
class element;
}  // namespace document
 
namespace types {
namespace bson_value {
 
class value;
 
class BSONCXX_API view {
   public:
#define BSONCXX_ENUM(type, val) explicit view(b_##type) noexcept;
#include <bsoncxx/enums/type.hpp>
#undef BSONCXX_ENUM
 
    view() noexcept;
 
    view(const view&) noexcept;
    view& operator=(const view&) noexcept;
 
    ~view();
 
    friend BSONCXX_API bool BSONCXX_CALL operator==(const bson_value::view&,
                                                    const bson_value::view&);
    friend BSONCXX_API bool BSONCXX_CALL operator!=(const bson_value::view&,
                                                    const bson_value::view&);
 
    bsoncxx::type type() const;
 
    const b_double& get_double() const;
 
    const b_utf8& get_utf8() const;
 
    const b_document& get_document() const;
 
    const b_array& get_array() const;
 
    const b_binary& get_binary() const;
 
    const b_undefined& get_undefined() const;
 
    const b_oid& get_oid() const;
 
    const b_bool& get_bool() const;
 
    const b_date& get_date() const;
 
    const b_null& get_null() const;
 
    const b_regex& get_regex() const;
 
    const b_dbpointer& get_dbpointer() const;
 
    const b_code& get_code() const;
 
    const b_symbol& get_symbol() const;
 
    const b_codewscope& get_codewscope() const;
 
    const b_int32& get_int32() const;
 
    const b_timestamp& get_timestamp() const;
 
    const b_int64& get_int64() const;
 
    const b_decimal128& get_decimal128() const;
 
    const b_minkey& get_minkey() const;
 
    const b_maxkey& get_maxkey() const;
 
   private:
    friend class document::element;
    friend class bson_value::value;
 
    view(const std::uint8_t* raw, std::uint32_t length, std::uint32_t offset, std::uint32_t keylen);
    view(void* internal_value) noexcept;
 
    void _init(void* internal_value) noexcept;
 
    void BSONCXX_PRIVATE destroy() noexcept;
 
    bsoncxx::type _type;
    union {
        struct b_double _b_double;
        struct b_utf8 _b_utf8;
        struct b_document _b_document;
        struct b_array _b_array;
        struct b_binary _b_binary;
        struct b_undefined _b_undefined;
        struct b_oid _b_oid;
        struct b_bool _b_bool;
        struct b_date _b_date;
        struct b_null _b_null;
        struct b_regex _b_regex;
        struct b_dbpointer _b_dbpointer;
        struct b_code _b_code;
        struct b_symbol _b_symbol;
        struct b_codewscope _b_codewscope;
        struct b_int32 _b_int32;
        struct b_timestamp _b_timestamp;
        struct b_int64 _b_int64;
        struct b_decimal128 _b_decimal128;
        struct b_minkey _b_minkey;
        struct b_maxkey _b_maxkey;
    };
};
 
// sfinae in the bool return to avoid competing with the value == value
// operators.
template <typename T>
using not_view = typename std::enable_if<
    std::is_constructible<bson_value::view, T>::value &&
        !std::is_same<typename std::decay<T>::type, bson_value::view>::value &&
        !std::is_same<typename std::decay<T>::type, bson_value::value>::value,
    bool>::type;
 
template <typename T>
BSONCXX_INLINE not_view<T> operator==(const bson_value::view& lhs, T&& rhs) {
    return lhs == bson_value::view{std::forward<T>(rhs)};
}
 
template <typename T>
BSONCXX_INLINE not_view<T> operator==(T&& lhs, const bson_value::view& rhs) {
    return bson_value::view{std::forward<T>(lhs)} == rhs;
}
 
template <typename T>
BSONCXX_INLINE not_view<T> operator!=(const bson_value::view& lhs, T&& rhs) {
    return lhs != bson_value::view{std::forward<T>(rhs)};
}
 
template <typename T>
BSONCXX_INLINE not_view<T> operator!=(T&& lhs, const bson_value::view& rhs) {
    return bson_value::view{std::forward<T>(lhs)} != rhs;
}
 
}  // namespace bson_value
}  // namespace types
 
BSONCXX_INLINE_NAMESPACE_END
}  // namespace bsoncxx
 
#include <bsoncxx/config/postlude.hpp>