From: Wolfgang Bangerth <bangerth@colostate.edu>
Date: Sun, 27 Feb 2022 00:35:34 +0000 (-0700)
Subject: Add to the documentation.
X-Git-Tag: v9.4.0-rc1~413^2~1
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=313dbf1874bd3548962ea98b23c3bc0bb7aab4ea;p=dealii.git

Add to the documentation.
---

diff --git a/include/deal.II/base/mpi.h b/include/deal.II/base/mpi.h
index c8ba9fad27..18f98bb3d6 100644
--- a/include/deal.II/base/mpi.h
+++ b/include/deal.II/base/mpi.h
@@ -1471,6 +1471,12 @@ namespace Utilities
      * via MPI functions to another process, and using
      * `mpi_type_id_for_type<decltype(obj)>` to infer the correct MPI type to
      * use for the communication.
+     *
+     * The type `T` given here must be one of the data types supported
+     * by MPI, such as `int` or `double`. It may not be an array of
+     * objects of such a type, or a pointer to an object of such a
+     * type. The compiler will produce an error if this requirement is
+     * not satisfied.
      */
     template <typename T>
     const MPI_Datatype