Conversion to const char*

[Kolhun]

At startup, the program crashes, I assume that the problem is in the convert method (if you do as in the first argument, the conversion first into a string and then into characters, then everything is OK) How can this be corrected? Code below

(Yes, the setValue method takes const char*)

///
const char* convert(std::string content)
{
const char* defined = content.c_str();
return defined;
}

[gregmarr]

This has nothing to do with the library. Your convert function is returning a pointer from a temporary std::string (it's passed by value instead of reference), so it's invalid as soon as the function returns.

[Kolhun]

I try and it doesn't work, maybe I'm not doing it right?

[gregmarr]

If that is all that your convert function is doing, then you don't even need the function, just call .c_str() directly.

[Kolhun]

Yes, that's all it does, and no, it doesn't work that way either

The point is that the section of code associated with defId is working properly, but the method is not

[gregmarr]

That's because dataResult["id"] isn't a std::string, it's a json. You need to convert it to a std::string as you did with _id.

dataResult["id"].get<std::string>().c_str()

or to be safer if you don't know for sure that there is an "id" child in dataResult

dataResult.value<std::string>("id", "some default value").c_str()

Note that this is STILL a temporary, and it will be destroyed as soon as the statement finishes, so ini.SetValue needs to copy the string, but at least now it survives the call to ini.SetValue(). This applies to both const char * parameters to ini.SetValue(), as defId dies when _id is destroyed.

[Kolhun]

That's how, and how can this be wrapped into a method? I tried to get into it, it didn't work out very well :D

[gregmarr]

You can't do that, as then you lose the magic lifetime extension.

You can do it with get_ref instead of get, so then the const char * lives as long as the json, which is better. https://www.godbolt.org/z/hWsYqceMK

[Kolhun]

Well, thank you, you helped me a lot)))