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< div class = "titlepage" >< div >< div >< h5 class = "title" >
< a name = "fusion.algorithm.iteration.metafunctions.fold" ></ a >< a href = "fold.html" title = "fold" > fold</ a ></ h5 ></ div ></ div ></ div >
< a name = "fusion.algorithm.iteration.metafunctions.fold.description" ></ a >< h6 >
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< a name = "id584198" ></ a >
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< a href = "fold.html#fusion.algorithm.iteration.metafunctions.fold.description" > Description</ a >
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Returns the result type of < a href = "../functions/fold.html" title = "fold" >< tt class = "computeroutput" >< span class = "identifier" > fold</ span ></ tt ></ a > .
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< a name = "fusion.algorithm.iteration.metafunctions.fold.synopsis" ></ a >< h6 >
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< a name = "id584248" ></ a >
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< a href = "fold.html#fusion.algorithm.iteration.metafunctions.fold.synopsis" > Synopsis</ a >
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< pre class = "programlisting" >
< span class = "keyword" > template</ span >< span class = "special" > < </ span >
< span class = "keyword" > typename</ span > < span class = "identifier" > Sequence</ span >< span class = "special" > ,</ span >
< span class = "keyword" > typename</ span > < span class = "identifier" > State</ span >< span class = "special" > ,</ span >
< span class = "keyword" > typename</ span > < span class = "identifier" > F</ span >< span class = "special" > > </ span >
< span class = "keyword" > struct</ span > < span class = "identifier" > fold</ span >
< span class = "special" > {</ span >
< span class = "keyword" > typedef</ span > < span class = "emphasis" >< em > unspecified</ em ></ span > < span class = "identifier" > type</ span >< span class = "special" > ;</ span >
< span class = "special" > };</ span >
</ pre >
< div class = "table" >
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< a name = "id584383" ></ a >< p class = "title" >< b > Table </ b ></ p >
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< table class = "table" summary = "Parameters" >
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Parameter
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Requirement
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</ th >
< th >
< p >
Description
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< tt class = "computeroutput" >< span class = "identifier" > Sequence</ span ></ tt >
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A model of < a href = "../../../sequence/concepts/forward_sequence.html" title = "Forward
Sequence" > Forward
Sequence</ a >
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The sequence to iterate
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< tt class = "computeroutput" >< span class = "identifier" > State</ span ></ tt >
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Any type
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The initial state for the first application of < tt class = "computeroutput" >< span class = "identifier" > F</ span ></ tt >
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< tt class = "computeroutput" >< span class = "identifier" > F</ span ></ tt >
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< tt class = "computeroutput" >< a href = "http://www.boost.org/libs/utility/utility.htm#result_of" target = "_top" >< tt class = "computeroutput" >< span class = "identifier" > boost</ span >< span class = "special" > ::</ span >< span class = "identifier" > result_of</ span ></ tt ></ a >< span class = "special" > < </ span >< span class = "identifier" > F</ span >< span class = "special" > (</ span >< span class = "identifier" > E</ span >< span class = "special" > ,</ span >< span class = "identifier" > S</ span >< span class = "special" > )> ::</ span >< span class = "identifier" > type</ span ></ tt > is the return type of < tt class = "computeroutput" >< span class = "identifier" > f</ span >< span class = "special" > (</ span >< span class = "identifier" > e</ span >< span class = "special" > ,</ span >< span class = "identifier" > s</ span >< span class = "special" > )</ span ></ tt >
for each element < tt class = "computeroutput" >< span class = "identifier" > e</ span ></ tt >
of type < tt class = "computeroutput" >< span class = "identifier" > E</ span ></ tt > in < tt class = "computeroutput" >< span class = "identifier" > seq</ span ></ tt > , and current state < tt class = "computeroutput" >< span class = "identifier" > s</ span ></ tt > of type < tt class = "computeroutput" >< span class = "identifier" > S</ span ></ tt >
</ p >
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The operation to be applied on forward traversal
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< a name = "fusion.algorithm.iteration.metafunctions.fold.expression_semantics" ></ a >< h6 >
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< a name = "id584733" ></ a >
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< a href = "fold.html#fusion.algorithm.iteration.metafunctions.fold.expression_semantics" > Expression
Semantics</ a >
</ h6 >
< pre class = "programlisting" >
< a href = "fold.html" title = "fold" >< tt class = "computeroutput" >< span class = "identifier" > result_of</ span >< span class = "special" > ::</ span >< span class = "identifier" > fold</ span ></ tt ></ a >< span class = "special" > < </ span >< span class = "identifier" > Sequence</ span >< span class = "special" > ,</ span > < span class = "identifier" > State</ span >< span class = "special" > ,</ span > < span class = "identifier" > F</ span >< span class = "special" > > ::</ span >< span class = "identifier" > type</ span >
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< span class = "bold" >< b > Return type</ b ></ span > : Any type
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< p >
< span class = "bold" >< b > Semantics</ b ></ span > : Returns the result of applying
< tt class = "computeroutput" >< span class = "identifier" > fold</ span ></ tt > to a sequence of
type < tt class = "computeroutput" >< span class = "identifier" > Sequence</ span ></ tt > , with an
initial state of type < tt class = "computeroutput" >< span class = "identifier" > State</ span ></ tt >
and binary function object or function pointer of type < tt class = "computeroutput" >< span class = "identifier" > F</ span ></ tt > .
</ p >
< a name = "fusion.algorithm.iteration.metafunctions.fold.complexity" ></ a >< h6 >
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< a name = "id584907" ></ a >
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< a href = "fold.html#fusion.algorithm.iteration.metafunctions.fold.complexity" > Complexity</ a >
</ h6 >
< p >
Linear, exactly < tt class = "computeroutput" >< a href = "../../../sequence/intrinsic/metafunctions/size.html" title = "size" >< tt class = "computeroutput" >< span class = "identifier" > result_of</ span >< span class = "special" > ::</ span >< span class = "identifier" > size</ span ></ tt ></ a >< span class = "special" > < </ span >< span class = "identifier" > Sequence</ span >< span class = "special" > > ::</ span >< span class = "identifier" > value</ span ></ tt > applications of < tt class = "computeroutput" >< span class = "identifier" > F</ span ></ tt > .
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< a name = "fusion.algorithm.iteration.metafunctions.fold.header" ></ a >< h6 >
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< a href = "fold.html#fusion.algorithm.iteration.metafunctions.fold.header" > Header</ a >
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< span class = "preprocessor" > #include</ span > < span class = "special" > < </ span >< span class = "identifier" > boost</ span >< span class = "special" > /</ span >< span class = "identifier" > fusion</ span >< span class = "special" > /</ span >< span class = "identifier" > algorithm</ span >< span class = "special" > /</ span >< span class = "identifier" > iteration</ span >< span class = "special" > /</ span >< span class = "identifier" > fold</ span >< span class = "special" > .</ span >< span class = "identifier" > hpp</ span >< span class = "special" > > </ span >
< span class = "preprocessor" > #include</ span > < span class = "special" > < </ span >< span class = "identifier" > boost</ span >< span class = "special" > /</ span >< span class = "identifier" > fusion</ span >< span class = "special" > /</ span >< span class = "identifier" > include</ span >< span class = "special" > /</ span >< span class = "identifier" > fold</ span >< span class = "special" > .</ span >< span class = "identifier" > hpp</ span >< span class = "special" > > </ span >
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< td align = "right" >< div class = "copyright-footer" > Copyright © 2001-2007 Joel de Guzman, Dan Marsden, Tobias
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Schwinger< p >
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at < a href = "http://www.boost.org/LICENSE_1_0.txt" target = "_top" > http://www.boost.org/LICENSE_1_0.txt</ a > )
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