Reading numbers as string leads to reading error

[Rooib]

Hi
I'm trying to read numbers as string which I enable through the glz::opts strcut. It proceeds to read numbers as strings just fine but seems to fail parsing json content which is defined as std::string.
Here's a simple example:

struct my_struct
{
    std::string i;
    std::string d;
    std::string hello;
};

int main(int const argc, char* argv[])
{

    constexpr glz::opts opts{.number = true};
    std::string const buffer = R"({"i":287,"d":3.14,"hello":"Hello World"})";

    my_struct value{};
    auto const error_ctx = glz::read<opts, my_struct>(value, buffer);
    if (error_ctx)
    {
        std::cout << "Error reading: " << glz::format_error(error_ctx, buffer);
    }
    else
    {
        std::cout << value.i << " " << value.d << " " << value.hello;
    }
    return EXIT_SUCCESS;
}

This leads to this error:

Error reading: 1:27: expected_comma
   {"i":287,"d":3.14,"hello":"Hello World"}

Am i doing something wrong here?

[stephenberry]

Thanks for your question. The number option mostly exists to facilitate the glz::number wrapper that allows you to individually define which std::string fields should be treated as number.

Your example shows that the error code is really unhelpful, and so I've updated the code in #1535 to return a parse_number_failure if the input is not a number.

In your case, setting the .number = true option globally tells Glaze to parse all types like std::string as numbers.

What you want is to use a meta to selectively parse only the strings that you want to be numbers:

template <>
struct glz::meta<my_struct>
{
   using T = numbers_as_strings2;
   static constexpr auto value = object("i", number<&T::i>, "d", number<&T::d>, &T::hello);
};

The meta defined above will solve your problem as long as you remove the global .number = true option.

Is this a sufficient solution for you?

[Rooib]

Thanks for the quick reply.
Using the your suggested number meta approach works for me.