Internal working of struct dtors

[Benjamin Thaut]

When looking at the output of __traits(AllMembers,) for one of my 
structs it lists me 3 destructors:

__dtor
__fieldDtor
__aggrDtor

Now I have some questions about these

1) What are they for? I figured that __dtor contains my custom dtor code 
and that both __fieldDtor and __aggrDtor call __dtor
2) On which conditions do you need to call which destructor? (assuming 
you want to destruct the struct manually)

if possible I do not want to take the route over the TypeInfo to destroy 
the struct because it introduces a indirect function call.

Kind Regards
Benjamin Thaut