Re: [eigen] Zero-Sized Blocks

[Christoph Hertzberg <chtz@xxxxxxxxxxxxxxxxxxxxxxxx>]

On 14.05.2013 13:06, Gael Guennebaud wrote:
> If this is already allowed for Matrix<> objects, then I don't see why
> this would not be the case for blocks.  It would be nice that the
> block.cpp unit test checks for 0-sized blocks.

For zero-sized matrices there is even a separate unit-test file.

Unit tests for blocks are not very extensive at the moment. If I see it 
correctly, only the case 2 rows and 5 cols is tested for fixed size 
blocks, and some methods such as topRows, etc are not tested at all (I 
might just have missed them).

If I find time to extend these tests, I'll also have a look at bug 579:
http://eigen.tuxfamily.org/bz/show_bug.cgi?id=579

btw:
Should fixed sized blocks which don't fit into fixed sized matrices fail 
at compile time? Currently they don't.
	Eigen::Matrix4d A;
// run-time assertion, which could be checked at compile-time:
	A.block<5,5>(0,0);

O.t.o.h. that might be a bit overkill, especially since there will be a 
lot of special cases for different dynamic/fixed combinations (and 
run-time assertions will still be needed anyways most of the time).


Christoph




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Dipl.-Inf., Dipl.-Math. Christoph Hertzberg
Cartesium 0.049
Universität Bremen
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