Merge pull request #48711 from leobeltra/update_README

Updated README

Author: cmsbuild

DataFormats/SoATemplate/README.md

@@ -1,6 +1,6 @@
 # Structure of array (SoA) generation
 
-The two header files [`SoALayout.h`](SoALayout.h) and [`SoAView.h`](SoAView.h) define preprocessor macros that
+The header file [`SoALayout.h`](SoALayout.h) defines preprocessor macros that
 allow generating SoA classes. The SoA classes generate multiple, aligned column from a memory buffer. The memory
 buffer is allocated separately by the user, and can be located in a memory space different from the local one (for
 example, a SoA located in a GPU device memory can be fully pre-defined on the host and the resulting structure is
@@ -30,21 +30,18 @@ alignment.
 
 ## View
 
-`SoAView` is a macro generated templated class allowing access to columns defined in one or multiple `SoALayout`s or
-`SoAViews`. The view can be generated in a constant and non-constant flavors. All view flavors provide with the same
-interface where scalar elements are accessed with an `operator()`: `soa.scalar()` while columns (Eigen or not) are
-accessed via a array of structure (AoS) -like syntax: `soa[index].x()`. The "struct" object returned by `operator[]`
-can be used as a shortcut: `auto si = soa[index]; si.z() = si.x() + zi.y();`
-
-A view can be instanciated by being passed the corresponding layout.
-
 Layout classes also define a `View` and `ConstView` subclass that provide access to each column and
 scalar of the layout. In addition to those fully parametrized templates, two others levels of parametrization are
 provided: `ViewTemplate`, `ViewViewTemplateFreeParams` and respectively `ConstViewTemplate`,
 `ConstViewTemplateFreeParams`. The parametrization of those templates is explained in the [Template
 parameters section](#template-parameters).
 
-It is also possible to build a generic `View` or `ConstView` passing from the [Metarecords sublass](#metarecords-subclass). 
+The view can be generated in a constant and non-constant flavors. All view flavors provide with the same
+interface where scalar elements are accessed with an `operator()`: `soa.scalar()` while columns (Eigen or not) are
+accessed via a array of structure (AoS) -like syntax: `soa[index].x()`. The "struct" object returned by `operator[]`
+can be used as a shortcut: `auto si = soa[index]; si.z() = si.x() + si.y();`
+
+A view can be instanciated by being passed the corresponding layout or passing from the [Metarecords subclass](#metarecords-subclass). 
 This view can point to data belonging to different SoAs and thus not contiguous in memory.
 
 ## Descriptor
@@ -199,40 +196,6 @@ AlignedBuffer h_buf (reinterpret_cast<std::byte*>(aligned_alloc(SoA1LayoutAligne
 SoA1LayoutAligned soaLayout(h_buf.get(), elements);
 ```
 
-A view will derive its column types from one or multiple layouts. The macro generating the view takes a list of layouts or views it
-gets is data from as a first parameter, and the selection of the columns the view will give access to as a second parameter.
-
-```C++
-// A 1 to 1 view of the layout (except for unsupported types).
-GENERATE_SOA_VIEW(SoA1ViewTemplate,
-  SOA_VIEW_LAYOUT_LIST(
-    SOA_VIEW_LAYOUT(SoA1Layout, soa1)
-  ),
-  SOA_VIEW_VALUE_LIST(
-    SOA_VIEW_VALUE(soa1, x),
-    SOA_VIEW_VALUE(soa1, y),
-    SOA_VIEW_VALUE(soa1, z),
-    SOA_VIEW_VALUE(soa1, color),
-    SOA_VIEW_VALUE(soa1, value),
-    SOA_VIEW_VALUE(soa1, py),
-    SOA_VIEW_VALUE(soa1, count),
-    SOA_VIEW_VALUE(soa1, anotherCount),
-    SOA_VIEW_VALUE(soa1, description),
-    SOA_VIEW_VALUE(soa1, someNumber)
-  )
-);
-
-using SoA1View = SoA1ViewTemplate<>;
-
-SoA1View soaView(soaLayout);
-
-for (size_t i=0; i < soaLayout.metadata().size(); ++i) {
-  auto si = soaView[i];
-  si.x() = si.y() = i;
-  soaView.someNumber() += i;
-}
-```
-
 The mutable and const views with the exact same set of columns and their parametrized variants are provided from the layout as:
 
 ```C++