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/*
* Copyright (c) 2011-2013 libbitcoin developers (see AUTHORS)
*
* This file is part of libbitcoin.
*
* libbitcoin is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License with
* additional permissions to the one published by the Free Software
* Foundation, either version 3 of the License, or (at your option)
* any later version. For more information see LICENSE.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef LIBBITCOIN_UTILITY_DECORATOR_HPP
#define LIBBITCOIN_UTILITY_DECORATOR_HPP
#include <functional>
namespace libbitcoin {
/*
* Defines a function decorator ala Python
*
* void foo(int x, int y);
* function<void ()> wrapper(function<void (int)> f);
*
* auto f = decorator(wrapper, bind(foo, 110, _1));
* f();
*/
template <typename Wrapper, typename Handler>
struct decorator_dispatch
{
Wrapper wrapper;
Handler handler;
template <typename... Args>
auto operator()(Args&&... args)
-> decltype(wrapper(handler)(std::forward<Args>(args)...))
{
return wrapper(handler)(std::forward<Args>(args)...);
}
};
template <typename Wrapper, typename Handler>
decorator_dispatch<
Wrapper,
typename std::decay<Handler>::type
>
decorator(Wrapper&& wrapper, Handler&& handler)
{
return {wrapper, handler};
}
} // namespace libbitcoin
#endif
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