[[no_unique_address]] to compact Triangulation_ds_full_cell #8045
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Successfully tested in CGAL-6.0-Ic-181 |
lrineau
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rm only: ready for master
lrineau
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the
rm only: ready for master
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Summary of Changes
When using the mirror policy,
combinatorics_ends with an array of dim+1int8_t, and Triangulation_ds_full_cell wants to store anunsigned charafter that. It seems natural for it to end up right after the array, however that's not what the Itanium ABI (used everywhere but windows) does, it leaves the padding at the end ofcombinatorics_alone and puts the extra member after that. IfCombinatoricswas a base class, reusing those padding bytes would work. With this ABI,[[no_unique_address]]precisely means to pretend that it is a base class, for the purpose of layout. I admit this is not the most common use for this attribute...With this change, it becomes tempting to make the mirror-index policy the default for static dimensions. Unless the user adds cell data that would perfectly fit the padding after
tds_databut would not fit anymore with the mirror indexes (not that far-fetched, I didn't check but that should be the case if the user data isintand the dimension is 3), the mirror indexes come for free (storage-wise) up to dimension 6, and at the cost of one extra (size of) pointer per full cell for dimensions 7 to 14. Maybe in a later PR...Release Management