Function json_isdigit

src/univalue/lib/univalue_read.cpp:19–22

static const size_t MAX_JSON_DEPTH = 512;

static bool json_isdigit(int ch)
{
    return ((ch >= '0') && (ch <= '9'));
}

// convert hexadecimal string to unsigned integer
static const char *hatoui(const char *first, const char *last,