Move sematics for adouble #94
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The adub data type is used to only store temporary values, and once an adub object is assigned to an adouble object it shall never be used again. Therefore, assignment of adub to adouble can be implemented just like move-assignment, without having to touch the tape at all. For this to work, the method signature has to change from (const adub&) to (adub&), because the value that is assigned is now modified (it is invalidated).
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Hi @osander1, due to architectural changes, the 'adub' could be removed. Until then, I would not review it. |
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The
adubclass seems to implement what modern C++ calls 'r-values' -- temporary objects that never get a name of their own. If this is true then it should be possible to get rid ofadubcompletely, and replace it by move-semantics foradouble. This MR contains a few first steps into that direction.Please test and review them thoroughly. I have not understood all the details yet. I have used the patches for a few weeks without problems, but there is one test failure testing
extdiff. Note that verifying that the patched code still runs and produces correct results is not enough: One has to check that the patches do not lead to longer tapes (which they shouldn't).