How register work?

[vipcxj]

For example I want to create many many logger and bind each to a object instance.

class Object {
  std::shared_ptr<spdlog::logger> m_logger;
}

When the object is destroied, will the logger be unregistered?
What about all m_loggers of objects with same name?
What about all m_loggers of objects with different name?
Will spdlog::set_level (set_pattern, set_formatter, set_err_handler) effect m_loggers?

[tt4g]

You need to register and unregister loggers to the spdlog registry with spdlog::register_logger() and spdlog::drop().
spdlog::* API affects all loggers registered in the registry.

spdlog::set_level() calls spdlog::logger::set_level() of the loggers registered in the registry.

spdlog identifies loggers registered in the registry by name (spdlog::logger::name()),
You can get it by passing the logger name to spdlog::get().

When the object is destroied, will the logger be unregistered?

No.

What about all m_loggers of objects with same name?
What about all m_loggers of objects with different name?

Loggers registered in the registry cannot use the same name.

Will spdlog::set_level (set_pattern, set_formatter, set_err_handler) effect m_loggers?

Yes.

[vipcxj]

@tt4g Can I use the logger without register it? Then when the object is destroyed, will m_logger be safely destroyed?

[tt4g]

You can use the logger without registering it in the registry.
However, it is no longer under the control of spdlog, so it is not affected by the spdlog::* API.

m_logger will be safely deleted if the destructor is called by std::shared_ptr.