from_msgpack() [4/4]

template<template< typename U, typename V, typename... Args > class ObjectType = std::map, template< typename U, typename... Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename IteratorType >

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::from_msgpack ( IteratorType  first, IteratorType  last, const bool  strict = true, const bool  allow_exceptions = true  )

inlinestatic

create a JSON value from an input in MessagePack format

Deserializes a given input i to a JSON value using the MessagePack serialization format.

The library maps MessagePack types to JSON value types as follows:

MessagePack type	JSON value type	first byte
positive fixint	number_unsigned	0x00..0x7F
fixmap	object	0x80..0x8F
fixarray	array	0x90..0x9F
fixstr	string	0xA0..0xBF
nil	null	0xC0
false	false	0xC2
true	true	0xC3
float 32	number_float	0xCA
float 64	number_float	0xCB
uint 8	number_unsigned	0xCC
uint 16	number_unsigned	0xCD
uint 32	number_unsigned	0xCE
uint 64	number_unsigned	0xCF
int 8	number_integer	0xD0
int 16	number_integer	0xD1
int 32	number_integer	0xD2
int 64	number_integer	0xD3
str 8	string	0xD9
str 16	string	0xDA
str 32	string	0xDB
array 16	array	0xDC
array 32	array	0xDD
map 16	object	0xDE
map 32	object	0xDF
bin 8	binary	0xC4
bin 16	binary	0xC5
bin 32	binary	0xC6
ext 8	binary	0xC7
ext 16	binary	0xC8
ext 32	binary	0xC9
fixext 1	binary	0xD4
fixext 2	binary	0xD5
fixext 4	binary	0xD6
fixext 8	binary	0xD7
fixext 16	binary	0xD8
negative fixint	number_integer	0xE0-0xFF

Note

Any MessagePack output created to_msgpack can be successfully parsed by from_msgpack.

Parameters

[in]	i	an input in MessagePack format convertible to an input adapter
[in]	strict	whether to expect the input to be consumed until EOF (true by default)
[in]	allow_exceptions	whether to throw exceptions in case of a parse error (optional, true by default)

Returns

deserialized JSON value; in case of a parse error and allow_exceptions set to false, the return value will be value_t::discarded.

Exceptions

parse_error.110	if the given input ends prematurely or the end of file was not reached when strict was set to true
parse_error.112	if unsupported features from MessagePack were used in the given input i or if the input is not valid MessagePack
parse_error.113	if a string was expected as map key, but not found

@complexity Linear in the size of the input i.

@liveexample{The example shows the deserialization of a byte vector in MessagePack format to a JSON value.,from_msgpack}

See also

http://msgpack.org

see to_msgpack(const basic_json&) for the analogous serialization

see from_cbor(InputType&&, const bool, const bool, const cbor_tag_handler_t) for the related CBOR format

see from_ubjson(InputType&&, const bool, const bool) for the related UBJSON format

see from_bson(InputType&&, const bool, const bool) for the related BSON format

Since

version 2.0.9; parameter start_index since 2.1.1; changed to consume input adapters, removed start_index parameter, and added strict parameter since 3.0.0; added allow_exceptions parameter since 3.2.0

Definition at line 25610 of file json.hpp.

    {
        basic_json result;
        detail::json_sax_dom_parser<basic_json> sdp(result, allow_exceptions);
        auto ia = detail::input_adapter(std::move(first), std::move(last));
        const bool res = binary_reader<decltype(ia)>(std::move(ia)).sax_parse(input_format_t::msgpack, &sdp, strict);
        return res ? result : basic_json(value_t::discarded);
    }