yuzu/externals/vcpkg/buildtrees/boost-phoenix/src/ost-1.79.0-b42fb470fd.clean/doc/actors.qbk
2022-11-05 15:35:56 +01:00

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[/==============================================================================
Copyright (C) 2001-2010 Joel de Guzman
Copyright (C) 2001-2005 Dan Marsden
Copyright (C) 2001-2010 Thomas Heller
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)
===============================================================================/]
[section Actor]
The `Actor` is the main concept behind the library. Actors are function objects.
An actor can accept 0 to `BOOST_PHOENIX_LIMIT` arguments.
[note You can set `BOOST_PHOENIX_LIMIT`, the predefined maximum arity an
actor can take. By default, `BOOST_PHOENIX_LIMIT` is set to 10.]
Phoenix supplies an `actor` class template whose specializations
model the `Actor` concept. `actor` has one template parameter, `Expr`,
that supplies the underlying expression to evaluate.
template <typename Expr>
struct actor
{
return_type
operator()() const;
template <typename T0>
return_type
operator()(T0& _0) const;
template <typename T0, typename T1>
return_type
operator()(T0& _0, T1& _1) const;
//...
};
The actor class accepts the arguments through a set of function call operators
for 0 to `BOOST_PHOENIX_LIMIT` arities (Don't worry about the details, for now. Note, for example,
that we skimp over the details regarding `return_type`). The arguments are passed through to
the evaluation mechanism. For more information see [link phoenix.inside.actor Inside Actors].
[endsect]