/usr/include/boost/beast/core
Edit: /usr/include/boost/beast/core/saved_handler.hpp (3788B)
//
// Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
//
// 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)
//
// Official repository: https://github.com/boostorg/beast
//
#ifndef BOOST_BEAST_CORE_SAVED_HANDLER_HPP
#define BOOST_BEAST_CORE_SAVED_HANDLER_HPP
#include
namespace boost {
namespace beast {
/** An invocable, nullary function object which holds a completion handler.
This container can hold a type-erased instance of any completion
handler, or it can be empty. When the container holds a value,
the implementation maintains an instance of `net::executor_work_guard`
for the handler's associated executor. Memory is dynamically allocated
to store the completion handler, and the allocator may optionally
be specified. Otherwise, the implementation uses the handler's
associated allocator.
*/
class saved_handler
{
class base;
template
class impl;
base* p_ = nullptr;
public:
/// Default Constructor
saved_handler() = default;
/// Copy Constructor (deleted)
saved_handler(saved_handler const&) = delete;
/// Copy Assignment (deleted)
saved_handler& operator=(saved_handler const&) = delete;
/// Destructor
BOOST_BEAST_DECL
~saved_handler();
/// Move Constructor
BOOST_BEAST_DECL
saved_handler(saved_handler&& other) noexcept;
/// Move Assignment
BOOST_BEAST_DECL
saved_handler&
operator=(saved_handler&& other) noexcept;
/// Returns `true` if `*this` contains a completion handler.
bool
has_value() const noexcept
{
return p_ != nullptr;
}
/** Store a completion handler in the container.
Requires `this->has_value() == false`.
@param handler The completion handler to store.
The implementation takes ownership of the handler by performing a decay-copy.
@param alloc The allocator to use.
*/
template
void
emplace(Handler&& handler, Allocator const& alloc);
/** Store a completion handler in the container.
Requires `this->has_value() == false`. The
implementation will use the handler's associated
allocator to obtian storage.
@param handler The completion handler to store.
The implementation takes ownership of the handler by performing a decay-copy.
*/
template
void
emplace(Handler&& handler);
/** Discard the saved handler, if one exists.
If `*this` contains an object, it is destroyed.
@returns `true` if an object was destroyed.
*/
BOOST_BEAST_DECL
bool
reset() noexcept;
/** Unconditionally invoke the stored completion handler.
Requires `this->has_value() == true`. Any dynamic memory
used is deallocated before the stored completion handler
is invoked. The executor work guard is also reset before
the invocation.
*/
BOOST_BEAST_DECL
void
invoke();
/** Conditionally invoke the stored completion handler.
Invokes the stored completion handler if
`this->has_value() == true`, otherwise does nothing. Any
dynamic memory used is deallocated before the stored completion
handler is invoked. The executor work guard is also reset before
the invocation.
@return `true` if the invocation took place.
*/
BOOST_BEAST_DECL
bool
maybe_invoke();
};
} // beast
} // boost
#include
#ifdef BOOST_BEAST_HEADER_ONLY
#include
#endif
#endif