[Rcpp-devel] added raw support in RcppSexp

[Romain François]

On 12/22/2009 12:09 PM, Dirk Eddelbuettel wrote:
>
> On 22 December 2009 at 10:46, Romain François wrote:
> | Hi,
> |
> | I've just added raw vector support into the RcppSexp class, so it gains:
> |
> | RcppSexp(const Rbyte&  v);
> | RcppSexp(const std::vector<Rbyte>  &  v);
> | std::vector<Rbyte>        asStdVectorRaw() const;
> |
> | I've also added the appropriate examples in RcppSexpTests.r
>
> Neat, thanks, particularly
>
> +std::vector<Rbyte>  RcppSexp::asStdVectorRaw() const {
> +    int n = Rf_length(m_sexp);
> +    std::vector<Rbyte>  v(n);
> +    switch( TYPEOF(m_sexp) ){
> +    case RAWSXP:
> +    	{
> +    		v.assign( RAW(m_sexp), RAW(m_sexp)+n ) ;
> +    		break ;
> +    	}
>
> I've long wondered why/how/if we could assign more efficiently -- but STL
> Vectors don't let us just 'memcpy' a chunk.

I don't think you are guaranteed that the elements are contiguous, so I 
would not go down there.

> Would this 'more iterator like' assign(a,b) work for the types INTEGER, REAL
> too?

yep. I derived this from reading item 5 of Effective STL, and how the 
author is rambling about using range functions rather than looping around.

a and be can be int* which is what INTEGER(x) would give you.

> Dirk
>


-- 
Romain Francois
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http://romainfrancois.blog.free.fr
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