Rcpp Version 0.12.12
head.h
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1 // -*- mode: C++; c-indent-level: 4; c-basic-offset: 4; tab-width: 8 -*-
2 //
3 // head.h: Rcpp R/C++ interface class library -- head
4 //
5 // Copyright (C) 2010 - 2011 Dirk Eddelbuettel and Romain Francois
6 //
7 // This file is part of Rcpp.
8 //
9 // Rcpp is free software: you can redistribute it and/or modify it
10 // under the terms of the GNU General Public License as published by
11 // the Free Software Foundation, either version 2 of the License, or
12 // (at your option) any later version.
13 //
14 // Rcpp is distributed in the hope that it will be useful, but
15 // WITHOUT ANY WARRANTY; without even the implied warranty of
16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 // GNU General Public License for more details.
18 //
19 // You should have received a copy of the GNU General Public License
20 // along with Rcpp. If not, see <http://www.gnu.org/licenses/>.
21 
22 #ifndef Rcpp__sugar__head_h
23 #define Rcpp__sugar__head_h
24 
25 namespace Rcpp{
26 namespace sugar{
27 
28 template <int RTYPE, bool NA, typename T>
29 class Head : public Rcpp::VectorBase< RTYPE ,NA, Head<RTYPE,NA,T> > {
30 public:
33 
34  Head( const VEC_TYPE& object_, R_xlen_t n_ ) : object(object_), n(n_) {
35  if( n < 0 ){
36  n = object.size() + n ;
37  }
38  }
39 
40  inline STORAGE operator[]( R_xlen_t i ) const {
41  return object[ i ] ;
42  }
43  inline R_xlen_t size() const { return n; }
44 
45 private:
46  const VEC_TYPE& object ;
47  int n ;
48 } ;
49 
50 } // sugar
51 
52 template <int RTYPE,bool NA, typename T>
54  const VectorBase<RTYPE,NA,T>& t,
55  R_xlen_t n
56  ){
57  return sugar::Head<RTYPE,NA,T>( t, n ) ;
58 }
59 
60 } // Rcpp
61 #endif
62 
sugar::Head< RTYPE, NA, T > head(const VectorBase< RTYPE, NA, T > &t, R_xlen_t n)
Definition: head.h:53
STORAGE operator[](R_xlen_t i) const
Definition: head.h:40
Head(const VEC_TYPE &object_, R_xlen_t n_)
Definition: head.h:34
R_xlen_t size() const
Definition: head.h:43
Rcpp API.
Definition: algo.h:28
Rcpp::VectorBase< RTYPE, NA, T > VEC_TYPE
Definition: head.h:31
const VEC_TYPE & object
Definition: head.h:46
Rcpp::traits::storage_type< RTYPE >::type STORAGE
Definition: head.h:32