allocator_type array array_t at at at at at at back back basic_json basic_json basic_json basic_json basic_json basic_json basic_json basic_json begin begin boolean_t cbegin cend clear const_iterator const_pointer const_reference const_reverse_iterator count crbegin crend detail::external_constructor diff difference_type dump emplace emplace_back empty end end erase erase erase erase exception find find flatten from_cbor from_msgpack front front get get get get get get_allocator get_ptr get_ptr get_ref get_ref insert insert insert insert insert insert invalid_iterator is_array is_boolean is_discarded is_null is_number is_number_float is_number_integer is_number_unsigned is_object is_primitive is_string is_structured iterator iterator_wrapper iterator_wrapper json_serializer max_size meta number_float_t number_integer_t number_unsigned_t object object_t operator value_t operator ValueType operator!= operator!= operator!= operator+= operator+= operator+= operator+= operator< operator< operator< operator<< operator<< operator<= operator<= operator<= operator= operator== operator== operator== operator> operator> operator> operator>= operator>= operator>= operator>> operator>> operator[] operator[] operator[] operator[] operator[] operator[] operator[] operator[] operator[] operator[] other_error out_of_range parse parse parse parse parse parse parse_error parse_event_t parser_callback_t patch pointer push_back push_back push_back push_back rbegin rbegin reference rend rend reverse_iterator size size_type string_t swap swap swap swap to_cbor to_msgpack type type_error type_name unflatten value value value value value_t value_type ~basic_json

from_cbor() 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> static basic_json nlohmann::basic_json::from_cbor ( const std::vector< uint8_t > &  v, const size_t  start_index = 0  ) inlinestatic Deserializes a given byte vector v to a JSON value using the CBOR (Concise Binary Object Representation) serialization format. The library maps CBOR types to JSON value types as follows: CBOR type JSON value type first byte Integer number_unsigned 0x00..0x17 Unsigned integer number_unsigned 0x18 Unsigned integer number_unsigned 0x19 Unsigned integer number_unsigned 0x1a Unsigned integer number_unsigned 0x1b Negative integer number_integer 0x20..0x37 Negative integer number_integer 0x38 Negative integer number_integer 0x39 Negative integer number_integer 0x3a Negative integer number_integer 0x3b Negative integer number_integer 0x40..0x57 UTF-8 string string 0x60..0x77 UTF-8 string string 0x78 UTF-8 string string 0x79 UTF-8 string string 0x7a UTF-8 string string 0x7b UTF-8 string string 0x7f array array 0x80..0x97 array array 0x98 array array 0x99 array array 0x9a array array 0x9b array array 0x9f map object 0xa0..0xb7 map object 0xb8 map object 0xb9 map object 0xba map object 0xbb map object 0xbf False false 0xf4 True  true 0xf5 Nill null 0xf6 Half-Precision Float number_float 0xf9 Single-Precision Float number_float 0xfa Double-Precision Float number_float 0xfb Warning The mapping is incomplete in the sense that not all CBOR types can be converted to a JSON value. The following CBOR types are not supported and will yield parse errors (parse_error.112): byte strings (0x40..0x5f) date/time (0xc0..0xc1) bignum (0xc2..0xc3) decimal fraction (0xc4) bigfloat (0xc5) tagged items (0xc6..0xd4, 0xd8..0xdb) expected conversions (0xd5..0xd7) simple values (0xe0..0xf3, 0xf8) undefined (0xf7) CBOR allows map keys of any type, whereas JSON only allows strings as keys in object values. Therefore, CBOR maps with keys other than UTF-8 strings are rejected (parse_error.113). Note Any CBOR output created to_cbor can be successfully parsed by from_cbor. Parameters [in] v a byte vector in CBOR format [in] start_index the index to start reading from v (0 by default) Returns deserialized JSON value Exceptions parse_error.110 if the given vector ends prematurely parse_error.112 if unsupported features from CBOR were used in the given vector v or if the input is not valid CBOR parse_error.113 if a string was expected as map key, but not found Complexity Linear in the size of the byte vector v. Example The example shows the deserialization of a byte vector in CBOR format to a JSON value. #include "json.hpp" #include <iomanip> // for std::setw using json = nlohmann::json; int main() { // create byte vector std::vector<uint8_t> v = {0xa2, 0x67, 0x63, 0x6f, 0x6d, 0x70, 0x61, 0x63, 0x74, 0xf5, 0x66, 0x73, 0x63, 0x68, 0x65, 0x6d, 0x61, 0x00 }; // deserialize it with CBOR json j = json::from_cbor(v); // print the deserialized JSON value std::cout << std::setw(2) << j << std::endl; } Output (play with this example online): { "compact": true, "schema": 0 } The example code above can be translated with g++ -std=c++11 -Isrc doc/examples/from_cbor.cpp -o from_cbor See also http://cbor.io to_cbor(const basic_json&) for the analogous serialization from_msgpack(const std::vector<uint8_t>&, const size_t) for the related MessagePack format Since version 2.0.9, parameter start_index since 2.1.1 Definition at line 9361 of file json.hpp.