Array types

[Gareth Charnock]

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>
> The (C) arrays are not the same thing as dynamic arrays of dynamic arrays because:
> - Some algorithms are not designed for a triangle where rows may differ in length. Testing that rows are all the same length at runtime wastes time, and if you don't test it then it may cause bugs;
> - Sometimes you want to reshape a 2D matrix, so it's useful to store the matrix in contiguous memory;
> - Sometimes you need complex slicing, for example removal of some columns and rows from a 2D matrix.
>
> Recently in D.learn we have discussed this a bit.
>
> In C# there are both arrays of arrays as in D, and rectangular dynamic arrays, that are manages with a syntax similar to Pascal arrays: arr[x,y,z]. I think there is no so need to put them into D. But I think it's important to have a official type of them in Phobos, for example implemented as a struct (only the item type and number of dimensions are known at compile time):
>
> RectangularArray!(T, int ndimensions)
>
Well this might be a good time to mention that I've started to get back 
to working on that std.matrix proposal for Phobos from a few months 
back. Unfortunately, I wasn't able to work on it for a few months 
(personal reasons). However, this may only solve the problem for numeric 
types. On the other hand, with strategic use of __traits and static if....