Ichthyostega
f8517b7011
Since I've convinced myself during the last years that this kind of typelist programming is ''not a workaround'' — it is even superior to pattern matching on variadics for certain kinds of tasks — the empty struct defined as `NullType` got into more widespread use as a marker type in the Lumiera code base. It seems adequate though to give it a much more evocative name
65 lines
1.9 KiB
C++
65 lines
1.9 KiB
C++
/*
|
||
SESSION-SERVICE-FETCH.hpp - session implementation service API: fetch PlacementRef
|
||
|
||
Copyright (C)
|
||
2008, Hermann Vosseler <Ichthyostega@web.de>
|
||
|
||
**Lumiera** is free software; you can redistribute it and/or modify it
|
||
under the terms of the GNU General Public License as published by the
|
||
Free Software Foundation; either version 2 of the License, or (at your
|
||
option) any later version. See the file COPYING for further details.
|
||
|
||
*/
|
||
|
||
|
||
/** @file session-service-fetch.hpp
|
||
** Implementation level session API: resolve a Placement by hash-ID.
|
||
** This specialised service is intended to be used by PlacementRef,
|
||
** in order to (re)-access the Placement instance within the session,
|
||
** given the hash-ID of this placement. An implementation of this
|
||
** service is available through the SessionServices access mechanism.
|
||
**
|
||
** @see session-impl.hpp implementation of the service
|
||
** @see session-services.cpp implementation of access
|
||
**
|
||
*/
|
||
|
||
|
||
#ifndef MOBJECT_SESSION_SESSION_SERVICE_FETCH_H
|
||
#define MOBJECT_SESSION_SESSION_SERVICE_FETCH_H
|
||
|
||
//#include "steam/mobject/session.hpp"
|
||
//#include "lib/meta/generator.hpp"
|
||
#include "steam/mobject/placement.hpp"
|
||
|
||
|
||
|
||
|
||
namespace steam {
|
||
namespace mobject {
|
||
namespace session {
|
||
|
||
// using lib::meta::InstantiateChained;
|
||
// using lib::meta::InheritFrom;
|
||
// using lib::meta::Nil;
|
||
|
||
/**
|
||
* Implementation-level service for resolving an Placement-ID.
|
||
* Usually, this service is backed by the PlacementIndex of the
|
||
* current session -- however, for the purpose of unit testing,
|
||
* this index may be overlaid temporarily, by using the
|
||
* SessionServiceMockIndex API.
|
||
*/
|
||
class SessionServiceFetch
|
||
{
|
||
public:
|
||
static PlacementMO& resolveID (PlacementMO::ID const&) ;
|
||
static bool isRegisteredID (PlacementMO::ID const&) ;
|
||
|
||
static bool isAccessible() ;
|
||
};
|
||
|
||
|
||
|
||
}}} // namespace steam::mobject::session
|
||
#endif
|