2004-11-28 03:35:12 +00:00
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2004-11-28 03:35:12 +00:00
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< title > The MPL Reference Manual: reverse_iter_fold</ title >
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< table class = "header" >< tr class = "header" >< td class = "header-group navigation-bar" >< span class = "navigation-group" >< a href = "./reverse-fold.html" class = "navigation-link" > Prev</ a > < a href = "./accumulate.html" class = "navigation-link" > Next</ a ></ span >< span class = "navigation-group-separator" > | </ span >< span class = "navigation-group" >< a href = "./reverse-fold.html" class = "navigation-link" > Back</ a > < a href = "./accumulate.html" class = "navigation-link" > Along</ a ></ span >< span class = "navigation-group-separator" > | </ span >< span class = "navigation-group" >< a href = "./iteration-algorithms.html" class = "navigation-link" > Up</ a > < a href = "../refmanual.html" class = "navigation-link" > Home</ a ></ span >< span class = "navigation-group-separator" > | </ span >< span class = "navigation-group" >< a href = "./refmanual_toc.html" class = "navigation-link" > Full TOC</ a ></ span ></ td >
< td class = "header-group page-location" >< a href = "../refmanual.html" class = "navigation-link" > Front Page</ a > / < a href = "./algorithms.html" class = "navigation-link" > Algorithms</ a > / < a href = "./iteration-algorithms.html" class = "navigation-link" > Iteration Algorithms</ a > / < a href = "./reverse-iter-fold.html" class = "navigation-link" > reverse_iter_fold</ a ></ td >
</ tr ></ table >< div class = "header-separator" ></ div >
< div class = "section" id = "reverse-iter-fold" >
< h1 >< a class = "toc-backref" href = "./iteration-algorithms.html#id400" name = "reverse-iter-fold" > reverse_iter_fold</ a ></ h1 >
< div class = "section" id = "iteration-reverse-synopsis" >
< h3 >< a class = "subsection-title" href = "#synopsis" name = "synopsis" > Synopsis</ a ></ h3 >
< pre class = "literal-block" >
template<
typename Sequence
, typename State
, typename BackwardOp
, typename ForwardOp = _1
>
struct < a href = "./reverse-iter-fold.html" class = "identifier" > reverse_iter_fold</ a >
{
typedef < em > unspecified</ em > type;
};
</ pre >
</ div >
< div class = "section" id = "iteration-reverse-description" >
< h3 >< a class = "subsection-title" href = "#description" name = "description" > Description</ a ></ h3 >
< p > Returns the result of the successive application of binary < tt class = "literal" >< span class = "pre" > BackwardOp</ span ></ tt > to the
result of the previous < tt class = "literal" >< span class = "pre" > BackwardOp</ span ></ tt > invocation (< tt class = "literal" >< span class = "pre" > State</ span ></ tt > if it's the first call)
and each iterator in the range [< tt class = "literal" >< span class = "pre" >< a href = "./begin.html" class = "identifier" > begin</ a > < Sequence> ::type</ span ></ tt > , < tt class = "literal" >< span class = "pre" >< a href = "./end.html" class = "identifier" > end</ a > < Sequence> ::type</ span ></ tt > )
in reverse order. If < tt class = "literal" >< span class = "pre" > ForwardOp</ span ></ tt > is provided, then it's applied on forward
traversal to form the result which is passed to the first < tt class = "literal" >< span class = "pre" > BackwardOp</ span ></ tt > call.</ p >
</ div >
< div class = "section" id = "iteration-reverse-header" >
< h3 >< a class = "subsection-title" href = "#header" name = "header" > Header</ a ></ h3 >
< pre class = "literal-block" >
#include < < a href = "../../../../boost/mpl/reverse_iter_fold.hpp" class = "header" > boost/mpl/reverse_iter_fold.hpp</ a > >
</ pre >
</ div >
< div class = "section" id = "algorithms-iteration-reverse-parameters" >
< h3 >< a class = "subsection-title" href = "#parameters" name = "parameters" > Parameters</ a ></ h3 >
< table border = "1" class = "table" >
< colgroup >
< col width = "16%" />
< col width = "33%" />
< col width = "51%" />
</ colgroup >
< thead valign = "bottom" >
< tr >< th > Parameter</ th >
< th > Requirement</ th >
< th > Description</ th >
</ tr >
</ thead >
< tbody valign = "top" >
< tr >< td >< tt class = "literal" >< span class = "pre" > Sequence</ span ></ tt ></ td >
< td >< a class = "reference" href = "./forward-sequence.html" > Forward Sequence</ a ></ td >
< td > A sequence to iterate.</ td >
</ tr >
< tr >< td >< tt class = "literal" >< span class = "pre" > State</ span ></ tt ></ td >
< td > Any type</ td >
< td > The initial state for the first < tt class = "literal" >< span class = "pre" > BackwardOp</ span ></ tt >
/ < tt class = "literal" >< span class = "pre" > ForwardOp</ span ></ tt > application.</ td >
</ tr >
< tr >< td >< tt class = "literal" >< span class = "pre" > BackwardOp</ span ></ tt ></ td >
< td > Binary < a class = "reference" href = "./lambda-expression.html" > Lambda Expression</ a ></ td >
< td > The operation to be executed on backward
traversal.</ td >
</ tr >
< tr >< td >< tt class = "literal" >< span class = "pre" > ForwardOp</ span ></ tt ></ td >
< td > Binary < a class = "reference" href = "./lambda-expression.html" > Lambda Expression</ a ></ td >
< td > The operation to be executed on forward
traversal.</ td >
</ tr >
</ tbody >
</ table >
</ div >
< div class = "section" id = "iteration-reverse-expression-semantics" >
< h3 >< a class = "subsection-title" href = "#expression-semantics" name = "expression-semantics" > Expression semantics</ a ></ h3 >
< p > For any < a class = "reference" href = "./forward-sequence.html" > Forward Sequence</ a > < tt class = "literal" >< span class = "pre" > s</ span ></ tt > , binary < a class = "reference" href = "./lambda-expression.html" > Lambda Expression</ a > < tt class = "literal" >< span class = "pre" > backward_op</ span ></ tt > and < tt class = "literal" >< span class = "pre" > forward_op</ span ></ tt > ,
and arbitrary type < tt class = "literal" >< span class = "pre" > state</ span ></ tt > :</ p >
< pre class = "literal-block" >
typedef < a href = "./reverse-iter-fold.html" class = "identifier" > reverse_iter_fold</ a > < s,state,backward_op > ::type t;
</ pre >
< table class = "field-list" frame = "void" rules = "none" >
< col class = "field-name" />
< col class = "field-body" />
< tbody valign = "top" >
< tr class = "field" >< th class = "field-name" > Return type:</ th >< td class = "field-body" > A type.</ td >
</ tr >
< tr class = "field" >< th class = "field-name" > Semantics:</ th >< td class = "field-body" >< p class = "first" > Equivalent to</ p >
< pre class = "literal-block" >
typedef < a href = "./begin.html" class = "identifier" > begin</ a > < s> ::type i< sub > 1</ sub > ;
typedef < a href = "./next.html" class = "identifier" > next</ a > < i< sub > 1</ sub > > ::type i< sub > 2</ sub > ;
< em > ...</ em >
typedef < a href = "./next.html" class = "identifier" > next</ a > < i< sub > n</ sub > > ::type last;
typedef < a href = "./apply.html" class = "identifier" > apply</ a > < backward_op,state,i< sub > n</ sub > > ::type state< sub > n</ sub > ;
typedef < a href = "./apply.html" class = "identifier" > apply</ a > < backward_op,state< sub > n</ sub > ,i< sub > n-1</ sub > > ::type state< sub > n-1</ sub > ;
< em > ...</ em >
typedef < a href = "./apply.html" class = "identifier" > apply</ a > < backward_op,state< sub > 2</ sub > ,i< sub > 1</ sub > > ::type state< sub > 1</ sub > ;
typedef state< sub > 1</ sub > t;
</ pre >
< p class = "last" > where < tt class = "literal" >< span class = "pre" > n</ span > < span class = "pre" > ==</ span > < span class = "pre" >< a href = "./size.html" class = "identifier" > size</ a > < s> ::value</ span ></ tt > and < tt class = "literal" >< span class = "pre" > last</ span ></ tt > is identical to < tt class = "literal" >< span class = "pre" >< a href = "./end.html" class = "identifier" > end</ a > < s> ::type</ span ></ tt > ; equivalent
to < tt class = "literal" >< span class = "pre" > typedef</ span > < span class = "pre" > state</ span > < span class = "pre" > t;</ span ></ tt > if < tt class = "literal" >< span class = "pre" >< a href = "./empty.html" class = "identifier" > empty</ a > < s> ::value</ span > < span class = "pre" > ==</ span > < span class = "pre" > true</ span ></ tt > .</ p >
</ td >
</ tr >
</ tbody >
</ table >
<!-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -->
< pre class = "literal-block" >
typedef < a href = "./reverse-iter-fold.html" class = "identifier" > reverse_iter_fold</ a > < s,state,backward_op,forward_op > ::type t;
</ pre >
< table class = "field-list" frame = "void" rules = "none" >
< col class = "field-name" />
< col class = "field-body" />
< tbody valign = "top" >
< tr class = "field" >< th class = "field-name" > Return type:</ th >< td class = "field-body" > A type.</ td >
</ tr >
< tr class = "field" >< th class = "field-name" > Semantics:</ th >< td class = "field-body" >< p class = "first" > Equivalent to</ p >
< pre class = "last literal-block" >
typedef < a href = "./reverse-iter-fold.html" class = "identifier" > reverse_iter_fold</ a > <
Sequence
, < a href = "./iter-fold.html" class = "identifier" > iter_fold</ a > < s,state,forward_op> ::type
, backward_op
> ::type t;
</ pre >
</ td >
</ tr >
</ tbody >
</ table >
</ div >
< div class = "section" id = "iteration-reverse-complexity" >
< h3 >< a class = "subsection-title" href = "#complexity" name = "complexity" > Complexity</ a ></ h3 >
< p > Linear. Exactly < tt class = "literal" >< span class = "pre" >< a href = "./size.html" class = "identifier" > size</ a > < s> ::value</ span ></ tt > applications of < tt class = "literal" >< span class = "pre" > backward_op</ span ></ tt > and < tt class = "literal" >< span class = "pre" > forward_op</ span ></ tt > .</ p >
</ div >
< div class = "section" id = "iteration-reverse-example" >
< h3 >< a class = "subsection-title" href = "#example" name = "example" > Example</ a ></ h3 >
< p > Build a list of iterators to the negative elements in a sequence.</ p >
< pre class = "literal-block" >
typedef < a href = "./vector-c.html" class = "identifier" > vector_c</ a > < int,5,-1,0,-7,-2,0,-5,4> numbers;
typedef < a href = "./list-c.html" class = "identifier" > list_c</ a > < int,-1,-7,-2,-5> negatives;
typedef < a href = "./reverse-iter-fold.html" class = "identifier" > reverse_iter_fold</ a > <
numbers
, < a href = "./list.html" class = "identifier" > list</ a > <>
, < a href = "./if.html" class = "identifier" > if_</ a > < < a href = "./less.html" class = "identifier" > less</ a > < < a href = "./deref.html" class = "identifier" > deref</ a > < _2> ,< a href = "./int.html" class = "identifier" > int_</ a > < 0> > , < a href = "./push-front.html" class = "identifier" > push_front</ a > < _1,_2> , _1 >
> ::type iters;
< a href = "./assert.html" class = "identifier" > BOOST_MPL_ASSERT</ a > (( < a href = "./equal.html" class = "identifier" > equal</ a > <
negatives
, < a href = "./transform-view.html" class = "identifier" > transform_view</ a > < iters,< a href = "./deref.html" class = "identifier" > deref</ a > < _1> >
> ));
</ pre >
</ div >
< div class = "section" id = "iteration-reverse-see-also" >
< h3 >< a class = "subsection-title" href = "#see-also" name = "see-also" > See also</ a ></ h3 >
< p >< a class = "reference" href = "./algorithms.html" > Algorithms</ a > , < a class = "refentry reference" href = "./iter-fold.html" >< tt class = "refentry literal" >< span class = "pre" > iter_fold</ span ></ tt ></ a > , < a class = "refentry reference" href = "./reverse-fold.html" >< tt class = "refentry literal" >< span class = "pre" > reverse_fold</ span ></ tt ></ a > , < a class = "refentry reference" href = "./fold.html" >< tt class = "refentry literal" >< span class = "pre" > fold</ span ></ tt ></ a ></ p >
<!-- modtime: November 13, 2004 02:51:20 +0000 -->
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