From: Reza Rastak <rastak@stanford.edu>
Date: Thu, 28 May 2020 13:46:12 +0000 (-0400)
Subject: The constexpr paragraph moved to the correct place.
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F47%2Fhead;p=release-papers.git

The constexpr paragraph moved to the correct place.
---

diff --git a/9.2/paper.tex b/9.2/paper.tex
index f6aa4c7..b294407 100644
--- a/9.2/paper.tex
+++ b/9.2/paper.tex
@@ -248,21 +248,6 @@ that we briefly outline in the remainder of this section:
   solution. This, too, has been addressed in this release.
   \item \todo[inline]{Reza: Please add a short summary of the
     \texttt{DiscreteTime} class}
-\item Certain types of quantities in a simulation are constants fully known
-  at compile time. They can be pre-calculated and fully stored inside the
-  compiled program binary in order to avoid unnecessary initialization during
-  runtime. This optimization is now enabled for the class templates
-  \texttt{Tensor} and \texttt{SymmetricTensor} by qualifying their constructor,
-  member functions, and overloaded operators as \texttt{constexpr}.
-  For instance, the linear mechanical constitutive model for elastic solids
-  uses a constant fourth-order elasticity tensor
-  $\mathbb{C} = \lambda \boldsymbol{I} \otimes \boldsymbol{I} + 2 \mu \mathbb{I}$
-  which does not depend on the current state of strain.
-  This tensor can be statically initialized by defining it as
-  \texttt{constexpr SymmetricTensor<4, dim>}.
-  As another example, the lattice vectors in a crystal plasticity model are generally
-  constant and known during compilation time, enabling their efficient definition as
-  \texttt{constexpr Tensor<1, dim>}.
 \item z \todo[inline]{What else? Maybe mention the updated step-12?}
 \end{itemize}
 %
@@ -703,9 +688,26 @@ vectorization within an element~\cite{KronbichlerKormann2019} in the future.
 \subsection{Expanded use of C++11 facilities}
 \label{subsec:cxx}
 
-\todo[inline]{Reza: Short paragraph about constexpr}
-
-\todo[inline]{Mention as last sentence that next release will use C++14.}
+Certain types of quantities in a simulation are constants fully known
+at compile time. They can be pre-calculated and fully stored inside the
+compiled program binary in order to avoid unnecessary initialization during
+runtime. This optimization is now enabled for the class templates
+\texttt{Tensor} and \texttt{SymmetricTensor} by qualifying their constructor,
+member functions, and overloaded operators as \texttt{constexpr}.
+For instance, the linear mechanical constitutive model for elastic solids
+uses a constant fourth-order elasticity tensor
+$\mathbb{C} = \lambda \boldsymbol{I} \otimes \boldsymbol{I} + 2 \mu \mathbb{I}$
+which does not depend on the current state of strain.
+This tensor can be statically initialized by defining it as
+\texttt{constexpr SymmetricTensor<4, dim>}.
+As another example, the lattice vectors in a crystal plasticity model are generally
+constant and known during compilation time, enabling their efficient definition as
+\texttt{constexpr Tensor<1, dim>}.
+The capability of defining \texttt{constexpr} variables, functions, and methods
+was introduced by the C++11 standard and was later expanded by the C++14 standard.
+Therefore, the extent of \texttt{constexpr} support in \dealii{} depends on the C++
+standard which is used to compile the library. The next release of \dealii{}
+will fully adopt the features of the C++14 standard.
 
 
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