Question: return static json object from function

[ghost]

Hi,
forgive me but I'm a newbie with c++ in general.

I'm trying to use this library but I have a problem.
I have a file like this:

static json config;

json get_config()
{
   config["value"] = 456;
   return config;
}

void save_config()
{
   std::ofstream fout("config.txt");
   fout << std::setw(3) << config << std::endl;
}

in another file I do something like ...

auto obj = get_config();
obj["value"] = 123;
save_config();

but inside config.txt i still see old value (456).
How can I solve this ?

[Bosswestfalen]

Hi,

assuming the first code block is in file A and the second block is in file B.
When you call save_config() from file B the function uses the config object from file A, because you do not
pass an argument to the function. The function in file A does not know about the object from file B.

There are two ways to solve this problem, depending on what you want to do.
If you want to modify the static object make get_config() return a reference.
If you want to make a copy of the static object (that is what happens now) and store it, pass it to save_config.

Regards,
Bosswestfalen

[nlohmann]

@bdoblackfish Did this work for you?