Add comment explaining ViewProvider

This was only documented via examples (e.g. ViewProvider<GlTextureView>), but it's better to explain it properly in the header where the base case is defined.

PiperOrigin-RevId: 488813144
This commit is contained in:
Camillo Lugaresi 2022-11-15 18:34:07 -08:00 committed by Copybara-Service
parent a28ccb0964
commit 8b319e963a

View File

@ -18,6 +18,28 @@ namespace internal {
template <class... T>
struct types {};
// This template must be specialized for each view type V. Each specialization
// should define a pair of virtual methods called GetReadView and GetWriteView,
// whose first argument is a types<V> tag object. The result type and optional
// further arguments will depend on the view type.
//
// Example:
// template <>
// class ViewProvider<MyView> {
// public:
// virtual ~ViewProvider() = default;
// virtual MyView GetReadView(types<MyView>) const = 0;
// virtual MyView GetWriteView(types<MyView>) = 0;
// };
//
// The additional arguments and result type are reflected in GpuBuffer's
// GetReadView and GetWriteView methods.
//
// Using a type tag for the first argument allows the methods to be overloaded,
// so that a single storage can implement provider methods for multiple views.
// Since these methods are not template methods, they can (and should) be
// virtual, which allows storage classes to override them, enforcing that all
// storages providing a given view type implement the same interface.
template <class V>
class ViewProvider;