File mdbx.h++

The libmdbx C++ API header file. More...

#include <algorithm>
#include <cassert>
#include <climits>
#include <cstring>
#include <exception>
#include <ostream>
#include <sstream>
#include <stdexcept>
#include <string>
#include <type_traits>
#include <utility>
#include <vector>
#include "mdbx.h"

Namespaces

Type	Name
namespace	mdbx The libmdbx C++ API namespace.
namespace	allocation_aware_details
namespace	std STL namespace.

Classes

Type	Name
struct	bad_map_id
struct	bad_transaction
struct	bad_value_size
class	buffer <class ALLOCATOR, typename CAPACITY_POLICY> The chunk of data stored inside the buffer or located outside it.
struct	capacity_holder
struct	inplace_flag_holder
struct	stub_allocated_holder
struct	buffer_pair_spec <typename ALLOCATOR, typename CAPACITY_POLICY>
struct	buffer_tag Type tag for delivered buffer template classes.
class	cache_entry Cache entry for the transparent read-your-writes caching, see txn::get_cached() andmdbx_cache_get() .
class	cursor Unmanaged cursor.
struct	estimate_result
struct	move_result
class	cursor_managed Managed cursor.
struct	dangling_map_id
struct	db_corrupted
struct	db_full
struct	db_invalid
struct	db_too_large
struct	db_unable_extend
struct	db_version_mismatch
struct	db_wanna_write_for_recovery
struct	default_capacity_policy
struct	duplicated_lck_file
class	env Unmanaged database environment.
struct	geometry Database geometry for size management.
struct	size Tagged type for output to std::ostream.
struct	limits
struct	operate_options Operate options.
struct	operate_parameters Operate parameters.
struct	reader_info Reader information.
struct	reclaiming_options Garbage reclaiming options.
struct	sysraminfo Information about the system RAM, see mdbx_get_sysraminfo() .
class	env_managed Managed database environment.
struct	create_parameters Additional parameters for creating a new database.
class	error Implements error information and throwing corresponding exceptions.
class	exception Base class for all libmdbx's exceptions that correspond to libmdbx errors.
class	exception_thunk Transfers C++ exceptions thru C callbacks.
class	fatal Fatal exception that leads to termination anyway in dangerous unrecoverable cases.
struct	from_base58 Base58 decoder which satisfySliceTranscoder concept.
struct	from_base64 Base64 decoder which satisfySliceTranscoder concept.
struct	from_hex Hexadecimal decoder which satisfy SliceTranscoder concept.
struct	incompatible_operation
struct	internal_page_full
struct	internal_problem
struct	key_exists
struct	key_mismatch
struct	laggard_reader
struct	map_handle A handle for an individual table (aka key-value space, maps or sub-database) in the environment.
struct	info
struct	max_maps_reached
struct	max_readers_reached
struct	multivalue
struct	mvcc_retarded
struct	no_data
struct	not_found
struct	operation_not_permitted
struct	pair Combines pair of slices for key and value to represent result of certain operations.
struct	pair_result Combines pair of slices for key and value with boolean flag to represent result of certain operations.
struct	permission_denied_or_not_writeable
struct	reader_slot_busy
struct	remote_media
struct	slice References a data located outside the slice.
struct	something_busy
struct	thread_mismatch
struct	to_base58 Base58 encoder which satisfySliceTranscoder concept.
struct	to_base64 Base64 encoder which satisfySliceTranscoder concept.
struct	to_hex Hexadecimal encoder which satisfy SliceTranscoder concept.
struct	transaction_full
struct	transaction_ousted
struct	transaction_overlapping
class	txn Unmanaged database transaction.
class	txn_managed Managed database transaction.
struct	value_result Combines data slice with boolean flag to represent result of certain operations.
struct	hash<::mdbx::buffer< ALLOCATOR, CAPACITY_POLICY > > <class ALLOCATOR, typename CAPACITY_POLICY>
struct	hash<::mdbx::cursor > <>
struct	hash<::mdbx::env > <>
struct	hash<::mdbx::map_handle > <>
struct	hash<::mdbx::slice > <>
struct	hash<::mdbx::txn > <>

Public Types

Type	Name
union	bin

Macros

Type	Name
define	MDBX_ASSERT_CXX20_CONCEPT_SATISFIED (CONCEPT, TYPE) `static\_assert(CONCEPT<TYPE>)`
define	MDBX_CONSTEXPR_ASSERT (expr) `((expr) ? void(0) : [] { assert(!#expr); }())`
define	MDBX_CXX01_CONSTEXPR_ENUM `[MDBX\_CXX01\_CONSTEXPR](group__api__macros.md#define-mdbx_cxx01_constexpr)`
define	MDBX_CXX11_CONSTEXPR_ENUM `[MDBX\_CXX11\_CONSTEXPR](group__api__macros.md#define-mdbx_cxx11_constexpr)`
define	MDBX_CXX14_CONSTEXPR_ENUM `[MDBX\_CXX14\_CONSTEXPR](group__api__macros.md#define-mdbx_cxx14_constexpr)`
define	MDBX_CXX17_CONSTEXPR `constexpr`
define	MDBX_CXX17_CONSTEXPR_ENUM `[MDBX\_CXX17\_CONSTEXPR](mdbx_8h_09_09.md#define-mdbx_cxx17_constexpr)`
define	MDBX_CXX17_FALLTHROUGH `[[fallthrough]]`
define	MDBX_CXX20_CONSTEXPR `constexpr`
define	MDBX_CXX20_CONSTEXPR_ENUM `[MDBX\_CXX20\_CONSTEXPR](mdbx_8h_09_09.md#define-mdbx_cxx20_constexpr)`
define	MDBX_CXX20_LIKELY `[[likely]]`
define	MDBX_EXTERN_API_TEMPLATE (API_ATTRIBUTES, ...) `extern template class API\_ATTRIBUTES \_\_VA\_ARGS\_\_`
define	MDBX_IF_CONSTEXPR `constexpr`
define	MDBX_INSTALL_API_TEMPLATE (API_ATTRIBUTES, ...) `template class \_\_VA\_ARGS\_\_`
define	MDBX_MSVC_DECLSPEC_EMPTY_BASES `/\* nope \*/`
define	MDBX_NODISCARD `[[nodiscard]]`
define	MDBX_USING_CXX_EXPERIMENTAL_FILESYSTEM `0`

Detailed Description

This file is part of the libmdbx amalgamated source code (v0.15.0-40-g9554ed2b at 2026-10-10T22:49:10Z).

libmdbx (aka MDBX) is an extremely fast, compact, powerful, embeddable, transactional key-value store, with Apache 2.0 license. MDBX has a specific set of properties and capabilities, focused on creating unique lightweight solutions with extraordinary performance.

Please visit https://libmdbx.dqdkfa.ru for more information, documentation, C++ API description and links to the origin git repo with the source code. Questions, feedback and suggestions are welcome to the Telegram' group https://t.me/libmdbx, MAX' chat https://max.ru/join/dKckvyuARxp1vRK-wnPur8zYCEkbR3OUOmpPWkWxp78.

Donations are welcome to ETH 0xD104d8f8B2dC312aaD74899F83EBf3EEBDC1EA3A, BTC bc1qzvl9uegf2ea6cwlytnanrscyv8snwsvrc0xfsu, SOL FTCTgbHajoLVZGr8aEFWMzx3NDMyS5wXJgfeMTmJznRi. Всё будет хорошо!

The libmdbx project has been completely relocated to the jurisdiction of the Russian Federation.

Note:

libmdbx is still open and provided with first-class free support.

Copyright:

SPDX-License-Identifier: Apache-2.0

Author:

Леонид Юрьев aka Leonid Yuriev leo@yuriev.ru

Date:

2020-2026

Public Types Documentation

union bin

Macro Definition Documentation

define MDBX_ASSERT_CXX20_CONCEPT_SATISFIED

#define MDBX_ASSERT_CXX20_CONCEPT_SATISFIED (
    CONCEPT,
    TYPE
) `static_assert(CONCEPT<TYPE>)`

define MDBX_CONSTEXPR_ASSERT

#define MDBX_CONSTEXPR_ASSERT (
    expr
) `((expr) ? void(0) : [] { assert(!#expr); }())`

Workaround for old compilers without support assertion inside constexpr functions.

define MDBX_CXX01_CONSTEXPR_ENUM

#define MDBX_CXX01_CONSTEXPR_ENUM `MDBX_CXX01_CONSTEXPR`

define MDBX_CXX11_CONSTEXPR_ENUM

#define MDBX_CXX11_CONSTEXPR_ENUM `MDBX_CXX11_CONSTEXPR`

define MDBX_CXX14_CONSTEXPR_ENUM

#define MDBX_CXX14_CONSTEXPR_ENUM `MDBX_CXX14_CONSTEXPR`

define MDBX_CXX17_CONSTEXPR

#define MDBX_CXX17_CONSTEXPR `constexpr`

Workaround for old compilers without properly support for C++17 constexpr

define MDBX_CXX17_CONSTEXPR_ENUM

#define MDBX_CXX17_CONSTEXPR_ENUM `MDBX_CXX17_CONSTEXPR`

define MDBX_CXX17_FALLTHROUGH

#define MDBX_CXX17_FALLTHROUGH `[[fallthrough]]`

define MDBX_CXX20_CONSTEXPR

#define MDBX_CXX20_CONSTEXPR `constexpr`

Workaround for old compilers without properly support for C++20 constexpr.

define MDBX_CXX20_CONSTEXPR_ENUM

#define MDBX_CXX20_CONSTEXPR_ENUM `MDBX_CXX20_CONSTEXPR`

define MDBX_CXX20_LIKELY

#define MDBX_CXX20_LIKELY `[[likely]]`

define MDBX_EXTERN_API_TEMPLATE

#define MDBX_EXTERN_API_TEMPLATE (
    API_ATTRIBUTES,
    ...
) `extern template class API_ATTRIBUTES __VA_ARGS__`

define MDBX_IF_CONSTEXPR

#define MDBX_IF_CONSTEXPR `constexpr`

Workaround for old compilers without properly support for C++20 if constexpr.

define MDBX_INSTALL_API_TEMPLATE

#define MDBX_INSTALL_API_TEMPLATE (
    API_ATTRIBUTES,
    ...
) `template class __VA_ARGS__`

define MDBX_MSVC_DECLSPEC_EMPTY_BASES

#define MDBX_MSVC_DECLSPEC_EMPTY_BASES `/* nope */`

define MDBX_NODISCARD

#define MDBX_NODISCARD `[[nodiscard]]`

Workaround for old compilers without [[nodiscard]] support

define MDBX_USING_CXX_EXPERIMENTAL_FILESYSTEM

#define MDBX_USING_CXX_EXPERIMENTAL_FILESYSTEM `0`

The documentation for this class was generated from the following file docs/mdbx.h++