2002-01-31 15:36:01 +00:00
|
|
|
<HTML><HEAD><TITLE>Boost PREPROCESSOR library</TITLE><BODY bgcolor="#FFFFFF">
|
|
|
|
|
|
|
|
|
|
<a href="index.htm"><IMG height=86 alt="c++boost.gif (8819 bytes)" src="../../../../c++boost.gif" width=277 align=center></a>
|
|
|
|
|
|
|
|
|
|
<hr>
|
|
|
|
|
|
|
|
|
|
<H1>#include <<a href="../../../../boost/preprocessor/list/fold_left.hpp">boost/preprocessor/list/fold_left.hpp</a>></H1>
|
|
|
|
|
|
|
|
|
|
<hr>
|
|
|
|
|
|
|
|
|
|
<H2><a name="BOOST_PP_LIST_FOLD_LEFT">#define BOOST_PP_LIST_FOLD_LEFT</a>(F,P,L)</H2>
|
|
|
|
|
<P>Iterates F(D,P,X) for each element X of the list L (from the left or the start of the list).</P>
|
|
|
|
|
|
|
|
|
|
<P>In other words,</P>
|
|
|
|
|
|
|
|
|
|
<PRE>
|
|
|
|
|
<a href="list_fold_left.htm#BOOST_PP_LIST_FOLD_LEFT">BOOST_PP_LIST_FOLD_LEFT</a>(F,P,L)
|
|
|
|
|
</PRE>
|
|
|
|
|
|
|
|
|
|
<P>expands to:</P>
|
|
|
|
|
|
|
|
|
|
<PRE>
|
|
|
|
|
F
|
|
|
|
|
( D
|
|
|
|
|
, ... F(D, F(D,P,<a href="list_at.htm#BOOST_PP_LIST_AT">BOOST_PP_LIST_AT</a>(L,0)), <a href="list_at.htm#BOOST_PP_LIST_AT">BOOST_PP_LIST_AT</a>(L,1)) ...
|
|
|
|
|
, <a href="list_at.htm#BOOST_PP_LIST_AT">BOOST_PP_LIST_AT</a>(L,<a href="dec.htm#BOOST_PP_DEC">BOOST_PP_DEC</a>(<a href="list_size.htm#BOOST_PP_LIST_SIZE">BOOST_PP_LIST_SIZE</a>(L))
|
|
|
|
|
)
|
|
|
|
|
</PRE>
|
|
|
|
|
|
2002-01-31 21:52:46 +00:00
|
|
|
<H3>Note</H3>
|
|
|
|
|
|
|
|
|
|
<P>Folding, or accumulation, is a very general pattern of computation.
|
2002-01-31 15:36:01 +00:00
|
|
|
Most list operations can be implemented in terms of folding.</P>
|
|
|
|
|
|
|
|
|
|
<H3>See</H3>
|
|
|
|
|
<UL>
|
|
|
|
|
<LI><a href="list_fold_right.htm#BOOST_PP_LIST_FOLD_RIGHT">BOOST_PP_LIST_FOLD_RIGHT</a>()
|
|
|
|
|
</UL>
|
|
|
|
|
|
|
|
|
|
<H3>Uses</H3>
|
|
|
|
|
<UL>
|
|
|
|
|
<LI><a href="while.htm#BOOST_PP_WHILE">BOOST_PP_WHILE</a>()
|
|
|
|
|
</UL>
|
|
|
|
|
|
|
|
|
|
<hr>
|
|
|
|
|
|
|
|
|
|
<p>(C) Copyright Housemarque Oy 2002</p>
|
|
|
|
|
|
|
|
|
|
<p>Permission to copy, use, modify, sell and distribute this document is granted
|
|
|
|
|
provided this copyright notice appears in all copies. This document is provided
|
|
|
|
|
"as is" without express or implied warranty, and with no claim as to its suitability
|
|
|
|
|
for any purpose.</p>
|
|
|
|
|
|
|
|
|
|
<p>Generated: <!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %b %Y" startspan --><!--webbot bot="Timestamp" endspan i-checksum="15246" --></p>
|
|
|
|
|
|
|
|
|
|
</BODY></HTML>
|
