operator[]() [2/8]

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>>

const_reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::operator[] ( const json_pointer &  ptr ) const

inline

access specified element via JSON Pointer

Uses a JSON pointer to retrieve a reference to the respective JSON value. No bound checking is performed. The function does not change the JSON value; no null values are created. In particular, the special value - yields an exception.

Parameters

[in]

ptr

JSON pointer to the desired element

Returns

const reference to the element pointed to by ptr

@complexity Constant.

Exceptions

parse_error.106	if an array index begins with '0'
parse_error.109	if an array index was not a number
out_of_range.402	if the array index '-' is used
out_of_range.404	if the JSON pointer can not be resolved

@liveexample{The behavior is shown in the example.,operatorjson_pointer_const}

Since

version 2.0.0

Definition at line 25945 of file json.hpp.

    {
        return ptr.get_unchecked(this);
    }