Feature request: Disallowing singleton override

[Arnagos]

There is currently no way to disallow tsyringe from overriding existing registrations for singletons. This would be really useful to prevent erroneously overriding existing registrations.

A good way to handle this is the SimpleInjector approach: https://simpleinjector.readthedocs.io/en/latest/howto.html#override-existing-registrations

[vhiairrassary]

👍 I encountered this error as well while trying to override singleton in child container. Disallowing it and/or having it mentioned in the documentation may be a good idea.