Re: [eigen] What is the 'correct' way to pass matrix results?

[Christoph Hertzberg <chtz@xxxxxxxxxxxxxxxxxxxxxxxx>]

On 18.05.2011 18:35, Hauke Heibel wrote:
> Ah, I see. But even here you need to know what you want to return.
>
> Consider this example:
>
> template<typename Derived>
> <whatgoeshere??>  foo(const MatrixBase<Derived>&  m)
> {
>    return m*m;
> }
>
> in C++0x that would be
>
> template<typename Derived>
> auto foo(const MatrixBase<Derived>&  m) ->  decltype(m*m)
> {
>    return m*m;
> }
>
> where you provide type information via decltype. What I mean is that
> as far as I can see, you are lost when the function becomes more
> complex and have to fall back to hand written expressions.

Yeah, I haven't actually programmed in C++0x so far, and was not aware 
of the exact syntax at the moment. Actually, I was wondering how the 
return type would be determined for multiple return statements (so the 
decltype actually makes a little sense ...)

Thanks for your inputs,
Christoph

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Dipl.-Inf. Christoph Hertzberg
Cartesium 0.051
Universität Bremen
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