Re: [eigen] Interesting C++ standard proposal

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On 13.11.2013 12:31, Ilja Honkonen wrote:
auto a = A.block(...);
does the user want a copy of the submatrix or a lightweight view?
Actually, an even more trivial example would be this:
auto B = A; // is B a reference or a copy?

Isn't auto& always needed in order to get a reference to a C++ or STL
object? It would be surprising if eigen behaved differently.

Yes, you are right, let me take back that example. I did not say what A is, though. If it was a Ref<> or a Map<>, the question remains -- calling .eval() on Ref<> does not change the return type (but that's essentially the same as with the block example).


Christoph


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