Can we please not continue hiding pointers behind typedefs? It's a bad pattern, and that it's fairly widely used isn't a good excuse to introduce further usages of it.
Why is it a bad pattern?
It hides what is passed by reference, and what by value, and it makes it a guessing game whether you need -> or . since you don't know whether it's a pointer or the actual object. All to save a * in parameter and variable declaration?...
FWIW I don't like that pattern either although it's used in many parts of our code-base.
But relatively few new ones, most of it is pretty old.
I do agree it's not particularly pretty pattern, but in this case it's fairly isolated in the mmgr sources, and I quite value the consistency in this part of the code (i.e. that aset.c, slab.c and generation.c all use the same approach). So I haven't changed this.
The attached v7 fixes the off-by-one error in slab.c, causing failures in test_decoding isolation tests, and renames Gen to Generation, as proposed by Petr.