Rcpp Version 0.12.12
tail.h
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1 // -*- mode: C++; c-indent-level: 4; c-basic-offset: 4; tab-width: 8 -*-
2 //
3 // tail.h: Rcpp R/C++ interface class library -- tail
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 //
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20 // along with Rcpp. If not, see <http://www.gnu.org/licenses/>.
21 
22 #ifndef Rcpp__sugar__tail_h
23 #define Rcpp__sugar__tail_h
24 
25 namespace Rcpp{
26 namespace sugar{
27 
28 template <int RTYPE, bool NA, typename T>
29 class Tail : public Rcpp::VectorBase< RTYPE ,NA, Tail<RTYPE,NA,T> > {
30 public:
33 
34  Tail( const VEC_TYPE& object_, R_xlen_t n_ ) : object(object_), start(0), n(n_) {
35  if( n > 0 ){
36  start = object.size() - n ;
37  } else {
38  start = -n ;
39  n = object.size() - start ;
40  }
41  }
42 
43  inline STORAGE operator[]( R_xlen_t i ) const {
44  return object[ start + i ] ;
45  }
46  inline R_xlen_t size() const { return n; }
47 
48 private:
49  const VEC_TYPE& object ;
50  R_xlen_t start, n ;
51 } ;
52 
53 } // sugar
54 
55 template <int RTYPE,bool NA, typename T>
57  const VectorBase<RTYPE,NA,T>& t,
58  R_xlen_t n
59  ){
60  return sugar::Tail<RTYPE,NA,T>( t, n ) ;
61 }
62 
63 } // Rcpp
64 #endif
65 
sugar::Tail< RTYPE, NA, T > tail(const VectorBase< RTYPE, NA, T > &t, R_xlen_t n)
Definition: tail.h:56
const VEC_TYPE & object
Definition: tail.h:49
R_xlen_t size() const
Definition: tail.h:46
R_xlen_t start
Definition: tail.h:50
Rcpp::traits::storage_type< RTYPE >::type STORAGE
Definition: tail.h:32
STORAGE operator[](R_xlen_t i) const
Definition: tail.h:43
Rcpp::VectorBase< RTYPE, NA, T > VEC_TYPE
Definition: tail.h:31
R_xlen_t n
Definition: tail.h:50
Rcpp API.
Definition: algo.h:28
Tail(const VEC_TYPE &object_, R_xlen_t n_)
Definition: tail.h:34