.. Metafunctions/Concepts//Lambda Expression |30

Lambda Expression

Description

A |Lambda Expression| is a compile-time invocable entity in either of the following two forms:

• |Metafunction Class|
• |Placeholder Expression|

Most of the MPL components accept either of those, and the concept gives us a consice way to describe these requirements.

Expression requirements

See corresponding |Metafunction Class| and |Placeholder Expression| specifications.

Models

• |always|
• |unpack_args|
• plus<_, int_<2> >
• if_< less<_1, int_<7> >, plus<_1,_2>, _1 >

See also

|Metafunctions|, |Placeholders|, |apply|, |lambda|

.. copyright:: Copyright 2001-2009 Aleksey Gurtovoy and David Abrahams 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)