On Sunday, 16 February 2014 at 23:47:08 UTC, Robin wrote:
I am not currently aware of the "move semantics" in D or what
it is called there. However, I am not quite sure if D does an
equally good job as C++ in determining if a value can be moved
or not. I have made some simple tests which showed me that the
swap-assignment and the move-constructor are never called in D
at code where C++ would certainly take them, instead D just
copies values which were in fact rvalues ... (Maybe I just
don't get the whole thing behind the scenes - and I am really
hoping it.)
What swap assignment, what move constructor? :)
Here are the rules for moving rvalues in D:
1) All anonymous rvalues are moved;
2) Named temporaries that are returned from functions are moved;
3) That's it :) No other guarantees are offered (i.e. compilers
may or may not try to be smart in other scenarios).
Sometimes when you want an explicit move you can use
std.algorithm.move function. But keep in mind that its current
implementation is incomplete (i.e. it doesn't handle immutability
properly).
This code illustrates it all:
http://dpaste.dzfl.pl/c050c9fccbb2
@All of you:
What I have done since the last time:
I have changed my mind - matrix is now a value type. However, I
wasn't sure about this step because I planned to implement
dense and sparse matrices which could inherit from a basic
matrix implementation in thus required to be classes.
Templates, perhaps?
