get_unchecked() [1/2]

template<typename BasicJsonType >

BasicJsonType & nlohmann::json_pointer< BasicJsonType >::get_unchecked ( BasicJsonType *  ptr ) const

inlineprivate

return a reference to the pointed to value

Note

This version does not throw if a value is not present, but tries to create nested values instead. For instance, calling this function with pointer "/this/that" on a null value is equivalent to calling operator[]("this").operator[]("that") on that value, effectively changing the null value to an object.

Parameters

[in]

ptr

a JSON value

Returns

reference to the JSON value pointed to by the JSON pointer

@complexity Linear in the length of the JSON pointer.

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.404	if the JSON pointer can not be resolved

Definition at line 13024 of file json.hpp.

    {
        for (const auto &reference_token : reference_tokens)
        {
            // convert null values to arrays or objects before continuing
            if (ptr->is_null())
            {
                // check if reference token is a number
                const bool nums =
                    std::all_of(reference_token.begin(), reference_token.end(),
                                [](const unsigned char x)
                {
                    return std::isdigit(x);
                });
                // change value to array for numbers or "-" or to object otherwise
                *ptr = (nums || reference_token == "-")
                       ? detail::value_t::array
                       : detail::value_t::object;
            }
 
            switch (ptr->type())
            {
                case detail::value_t::object:
                {
                    // use unchecked object access
                    ptr = &ptr->operator[](reference_token);
                    break;
                }
 
                case detail::value_t::array:
                {
                    if (reference_token == "-")
                    {
                        // explicitly treat "-" as index beyond the end
                        ptr = &ptr->operator[](ptr->m_value.array->size());
                    }
 
                    else
                    {
                        // convert array index to number; unchecked access
                        ptr = &ptr->operator[](array_index(reference_token));
                    }
 
                    break;
                }
 
                case detail::value_t::null:
                case detail::value_t::string:
                case detail::value_t::boolean:
                case detail::value_t::number_integer:
                case detail::value_t::number_unsigned:
                case detail::value_t::number_float:
                case detail::value_t::binary:
                case detail::value_t::discarded:
                default:
                    JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + reference_token + "'", *ptr));
            }
        }
 
        return *ptr;
    }