Header
-<boost/compressed_pair.hpp>
-
-All of the contents of <boost/compressed_pair.hpp> are -defined inside namespace boost.
- -The class compressed pair is very similar to std::pair, but if -either of the template arguments are empty classes, then the -"empty base-class optimisation" is applied to compress -the size of the pair.
- -template <class T1, class T2> + +Header + + + ++ + + +
All of the contents of <boost/compressed_pair.hpp> are defined inside + namespace boost.
+The class compressed pair is very similar to std::pair, but if either of the + template arguments are empty classes, then the "empty base-class optimisation" + is applied to compress the size of the pair.
+template <class T1, class T2> class compressed_pair { public: @@ -52,47 +41,35 @@ public: void swap(compressed_pair& y); };- -The two members of the pair can be accessed using the member -functions first() and second(). Note that not all member -functions can be instantiated for all template parameter types. -In particular compressed_pair can be instantiated for reference -and array types, however in these cases the range of constructors -that can be used are limited. If types T1 and T2 are the same -type, then there is only one version of the single-argument -constructor, and this constructor initialises both values in the -pair to the passed value.
- -Note that compressed_pair can not be instantiated if either of -the template arguments is a union type, unless there is compiler -support for boost::is_union, or if boost::is_union is specialised -for the union type.
- -Finally, a word of caution for Visual C++ 6 users: if either -argument is an empty type, then assigning to that member will -produce memory corruption, unless the empty type has a "do -nothing" assignment operator defined. This is due to a bug -in the way VC6 generates implicit assignment operators.
- -
- -Revised 08 May 2001
- -© Copyright boost.org 2000. 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.
- -Based on contributions by Steve Cleary, Beman Dawes, Howard -Hinnant and John Maddock.
- -Maintained by John -Maddock, the latest version of this file can be found at www.boost.org, and the boost -discussion list at www.yahoogroups.com/list/boost.
- -- +
The two members of the pair can be accessed using the member functions first() + and second(). Note that not all member functions can be instantiated for all + template parameter types. In particular compressed_pair can be instantiated for + reference and array types, however in these cases the range of constructors + that can be used are limited. If types T1 and T2 are the same type, then there + is only one version of the single-argument constructor, and this constructor + initialises both values in the pair to the passed value.
+Note that if either member is a POD type, then that member is not + zero-initialized by the compressed_pair default constructor: it's up to you to + supply an initial value for these types if you want them to have a default + value.
+Note that compressed_pair can not be instantiated if either of the template + arguments is a union type, unless there is compiler support for + boost::is_union, or if boost::is_union is specialised for the union type.
+Finally, a word of caution for Visual C++ 6 users: if either argument is an + empty type, then assigning to that member will produce memory corruption, + unless the empty type has a "do nothing" assignment operator defined. This is + due to a bug in the way VC6 generates implicit assignment operators.
+
+Revised 08 May 2001
+© Copyright boost.org 2000. 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.
+Based on contributions by Steve Cleary, Beman Dawes, Howard Hinnant and John + Maddock.
+Maintained by John Maddock, the + latest version of this file can be found at www.boost.org, + and the boost discussion list at www.yahoogroups.com/list/boost.
++