array_index()

template<typename BasicJsonType >

static BasicJsonType::size_type nlohmann::json_pointer< BasicJsonType >::array_index ( const std::string &  s )

inlinestaticprivate

Parameters

[in]

s

reference token to be converted into an array index

Returns

integer representation of s

Exceptions

parse_error.106	if an array index begins with '0'
parse_error.109	if an array index begins not with a digit
out_of_range.404	if string s could not be converted to an integer
out_of_range.410	if an array index exceeds size_type

Definition at line 12878 of file json.hpp.

    {
        using size_type = typename BasicJsonType::size_type;
 
        // error condition (cf. RFC 6901, Sect. 4)
        if (JSON_HEDLEY_UNLIKELY(s.size() > 1 && s[0] == '0'))
        {
            JSON_THROW(detail::parse_error::create(106, 0, "array index '" + s + "' must not begin with '0'", BasicJsonType()));
        }
 
        // error condition (cf. RFC 6901, Sect. 4)
        if (JSON_HEDLEY_UNLIKELY(s.size() > 1 && !(s[0] >= '1' && s[0] <= '9')))
        {
            JSON_THROW(detail::parse_error::create(109, 0, "array index '" + s + "' is not a number", BasicJsonType()));
        }
 
        std::size_t processed_chars = 0;
        unsigned long long res = 0;  // NOLINT(runtime/int)
        JSON_TRY
        {
            res = std::stoull(s, &processed_chars);
        }
        JSON_CATCH(std::out_of_range &)
        {
            JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + s + "'", BasicJsonType()));
        }
 
        // check if the string was completely read
        if (JSON_HEDLEY_UNLIKELY(processed_chars != s.size()))
        {
            JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + s + "'", BasicJsonType()));
        }
 
        // only triggered on special platforms (like 32bit), see also
        // https://github.com/nlohmann/json/pull/2203
        if (res >= static_cast<unsigned long long>((std::numeric_limits<size_type>::max)()))  // NOLINT(runtime/int)
        {
            JSON_THROW(detail::out_of_range::create(410, "array index " + s + " exceeds size_type", BasicJsonType())); // LCOV_EXCL_LINE
        }
 
        return static_cast<size_type>(res);
    }