Allow for move on Deferred logging

[diehard2]

I have some types that I'm perfectly comfortable moving for logging purposes. Would be a nice enhancement!

For instance, I create an nlohmann::json object with information I don't need after I log. Ideally I could just do

LOG_INFO(m_logger, "{}", std::move(my_json));

and avoid the copy altogether

[odygrd]

The issue is that we can't simply change the parameter from Arg const& to Arg&& in the encode method. Since the method isn't templated (only the class is), this creates a regular rvalue reference that only accepts moved values.

This would break all existing code that passes normal variables to the logging functions. To properly support both moved and non-moved arguments, we'd need to either make encode itself a template method or provide overloads - both requiring more significant changes to the architecture than just tweaking a parameter type.

It's a good feature request, but not as simple as it first appears

[diehard2]

thanks for the response. If possible at some point, would be really nice to have!