update() [2/2]

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>>

void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::update ( const_reference  j )

inline

updates a JSON object from another object, overwriting existing keys

Inserts all values from JSON object j and overwrites existing keys.

Parameters

[in]

j

JSON object to read values from

Exceptions

type_error.312

if called on JSON values other than objects; example: "cannot use update() with string"

@complexity O(N*log(size() + N)), where N is the number of elements to insert.

@liveexample{The example shows how update() is used.,update}

See also

https://docs.python.org/3.6/library/stdtypes.html#dict.update

Since

version 3.0.0

Definition at line 23693 of file json.hpp.

    {
        // implicitly convert null value to an empty object
        if (is_null())
        {
            m_type = value_t::object;
            m_value.object = create<object_t>();
            assert_invariant();
        }
 
        if (JSON_HEDLEY_UNLIKELY(!is_object()))
        {
            JSON_THROW(type_error::create(312, "cannot use update() with " + std::string(type_name()), *this));
        }
 
        if (JSON_HEDLEY_UNLIKELY(!j.is_object()))
        {
            JSON_THROW(type_error::create(312, "cannot use update() with " + std::string(j.type_name()), *this));
        }
 
        for (auto it = j.cbegin(); it != j.cend(); ++it)
        {
            m_value.object->operator[](it.key()) = it.value();
#if JSON_DIAGNOSTICS
            m_value.object->operator[](it.key()).m_parent = this;
#endif
        }
    }