c++boost.gif (8819 bytes)

#include <boost/preprocessor/list/fold_left.hpp>


#define BOOST_PP_LIST_FOLD_LEFT(F,P,L)

Iterates F(D,P,X) for each element X of the list L (from the left or the start of the list).

In other words,

  BOOST_PP_LIST_FOLD_LEFT(F,P,L)

expands to:

  F
  ( D
  , ... F(D, F(D,P,BOOST_PP_LIST_AT(L,0)), BOOST_PP_LIST_AT(L,1)) ...
  , BOOST_PP_LIST_AT(L,BOOST_PP_DEC(BOOST_PP_LIST_SIZE(L))
  )

Note that folding, or accumulation, is a very general pattern of computation. Most list operations can be implemented in terms of folding.

See

Uses


(C) Copyright Housemarque Oy 2002

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