Helper struct to determine whether a Loader has a Collection typedef.
*/
template<typename T>
-struct NeedsCollection
+struct NeedsCollection: public Sfinae
{
- struct Yes { char c[2]; };
- struct No { char c; };
-
template<typename U>
static Yes f(typename U::Collection *);
template<typename U>
static No f(...);
- enum { value = (sizeof(f<T>(0))==sizeof(Yes)) };
+ enum { value = Evaluate<sizeof(f<T>(0))>::value };
};
class CollectionItemTypeBase;
Collections can have sources for loading objects on demand. Automatic loading
only works on a non-const Collection. See class CollectionSource for details.
-A fallback collection can be designated as another way of loading items that
-are not present. Items retrieted from the fallback collection are shared
+As a last resort, a fallback collection can be designated for loading items
+that are not present. Items retrieted from the fallback collection are shared
between the collections, and are only deleted when all collections in the chain
have been destroyed.
*/
CollectionItemTypeBase *get_type_for_item(const Variant &) const;
protected:
+ /** Adds a source for automatically loading items. Sources are consulted
+ in the order they are added. */
void add_source(CollectionSource &);
- IO::Seekable *open_from_sources(const std::string &);
+public:
+ /** Opens a raw resource, without interpreting it as object data. Null is
+ returned if no such file is found. The caller must dispose of the returned
+ object when done with it. */
+ IO::Seekable *open_raw(const std::string &) const;
+
+protected:
+ IO::Seekable *open_from_sources(const std::string &n) { return open_raw(n); }
private:
void gather_names_from_sources(std::list<std::string> &, const CollectionItemTypeBase &) const;