asset.hpp File Reference

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Description

Steam-Layer Interface: Assets.

Declares the Asset top level Interface, the Asset::Ident identification tuple and the asset::ID primary key wrapper. Normally, Assets should be handled using asset::PAsset, a ref counting smart pointer.

These classes are placed into namespace asset and proc_interface.

Assets are handled by a hierarchy of interfaces. Below the top level Asset interface there are interfaces for various different Kinds of Assets, like asset::Media, asset::Proc, etc. Code utilising the specific properties of e.g. Media assets, will be implemented directly against the asset::Media interface. To make this feasible while at the same time being able to handle all asset Kinds in a uniform manner, we use a hierarchy of ID classes. These IDs are actually just thin wrappers around a hash value, but they carry a template parameter specifying the Asset Kind and the Asset Kind subinterfaces provide a overloaded getID method with a covariant return value. For example the asset::Media::getID returns an ID<Media>. By using the templated query function AssetManager::getAsset, we can get at references to the more specific subinterface asset::media just by using the ID value in a typesafe manner. This helps avoiding dynamic typing and switch-on-type, leading to more robust, extensible and clear code.

(Implementation detail: as g++ is not able to handle member function template instantiations completely automatic, we need to trigger some template instantiations at the end of assetmanager.cpp )

See also

assetmanager.hpp

media.hpp

Definition in file asset.hpp.

#include "lib/error.hpp"
#include "lib/nocopy.hpp"
#include "include/logging.h"
#include "steam/asset/category.hpp"
#include "lib/hash-value.h"
#include "lib/p.hpp"
#include <boost/type_traits/is_base_of.hpp>
#include <boost/operators.hpp>
#include <cstddef>
#include <string>
#include <vector>
#include <set>

Classes
class	Asset
	Superinterface describing especially bookkeeping properties. More...
class	ID< KIND >
	thin wrapper around a size_t hash ID used as primary key for all Asset objects. More...
struct	Asset::Ident
	a POD comprised of all the information sufficiently identifying any given Asset. More...
struct	is_pAsset< X >
	type trait for detecting a shared-ptr-to-asset More...
struct	is_pAsset< shared_ptr< A > >

Typedefs
typedef const ID< Asset > &	IDA
typedef lib::P< Asset >	PAsset
typedef lib::P< const Asset >	PcAsset

Functions
template<class A >
const PcAsset	pAsset (shared_ptr< A > const &subPtr)
	promote subtype-ptr to PAsset, e.g. More...

Namespaces
	steam
	Steam-Layer implementation namespace root.
	steam::asset
	The asset subsystem of the Steam-Layer.