diff options
Diffstat (limited to 'libs/flyweight/example/composite.cpp')
| -rw-r--r-- | libs/flyweight/example/composite.cpp | 15 |
1 files changed, 6 insertions, 9 deletions
diff --git a/libs/flyweight/example/composite.cpp b/libs/flyweight/example/composite.cpp index 8dcb2d716..1395f412d 100644 --- a/libs/flyweight/example/composite.cpp +++ b/libs/flyweight/example/composite.cpp @@ -1,6 +1,6 @@ /* Boost.Flyweight example of a composite design. * - * Copyright 2006-2010 Joaquin M Lopez Munoz. + * Copyright 2006-2014 Joaquin M Lopez Munoz. * Distributed under the Boost Software License, Version 1.0. * (See accompanying file LICENSE_1_0.txt or copy at * http://www.boost.org/LICENSE_1_0.txt) @@ -47,12 +47,10 @@ typedef flyweight<list_impl> list; /* list_impl must be hashable to be used by flyweight: If a * node is a std::string, its hash resolves to that of the string; - * if it is a vector of nodes, we compute the hash by combining - * the *addresses* of the stored flyweights' associated values: this is - * consistent because flyweight equality implies equality of reference. - * Using this trick instead of hashing the node values themselves - * allow us to do the computation without recursively descending down - * through the entire data structure. + * if it is a vector of flyweight nodes, we combine their corresponding + * hash values. As hashing a flyweight does not involve actually hashing + * its pointed-to value, the resulting computation does not recursively + * descend down the entire data structure. */ struct list_hasher:boost::static_visitor<std::size_t> @@ -68,8 +66,7 @@ struct list_hasher:boost::static_visitor<std::size_t> std::size_t res=0; for(list_elems::const_iterator it=elms.begin(),it_end=elms.end(); it!=it_end;++it){ - const list_impl* p=&it->get(); - boost::hash_combine(res,p); + boost::hash_combine(res,*it); } return res; } |