calculated_value

Synopsis

template <class T, class ValueType, class Tag>
struct calculated_value
{
  // unspecified
};

Description

Defines a [tmp_value](tmp_value.html)<T, Tag> with a public static ::value element. It will be initialised using the expression T::get_value().

Header

#include <mpllibs/metamonad/calculated_value.hpp>

Expression semantics

For any t, v and a types the following are equivalent:

calculated_value<t, v, a>::type
t

calculated_value<t, v, a>::tag
a

and the following is also provided:

static const v calculated_value<t, v, a>::value(t::get_value());

Example

struct nothing : calculated_value<nothing, std::string>
{
  static std::string get_value() { return "nothing"; }
};

Copyright Abel Sinkovics (abel at elte dot hu) 2011. 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

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