Added slides on ranges

Author: Sebastien Ponce

talk/C++Course.tex

@@ -149,6 +149,7 @@
 \input{morelanguage/lambda}
 \input{morelanguage/stl}
 \input{morelanguage/morestl}
+\input{morelanguage/ranges}
 \input{morelanguage/raii}
 \input{morelanguage/initialization}
 }

talk/morelanguage/constness.tex

@@ -1,4 +1,4 @@
-\subsection[const]{Constness}
+\subsection[cst]{Constness}
 
 \begin{frame}[fragile]
   \frametitlecpp[98]{Constness}

talk/morelanguage/morestl.tex

@@ -1,4 +1,4 @@
-\subsection{More STL}
+\subsection[More]{More STL}
 
 \begin{frame}[fragile]
   \frametitlecpp[17]{\texttt{std::string\_view}}

talk/morelanguage/ranges.tex

@@ -0,0 +1,84 @@
+\subsection[range]{Ranges}
+
+\begin{frame}[fragile]
+  \frametitlecpp[20]{Ranges}
+  \begin{block}{The range concept}
+    \begin{itemize}
+    \item A range is a group of items that you can iterate over
+    \item It must provide iterators to its beginning and end, obtainable via \mintinline{cpp}{std::range::begin} and \mintinline{cpp}{std::range::end}
+    \item Range concepts are located in \mintinline{cpp}{std::ranges} namespace
+    \item All STL containers are ranges
+    \end{itemize}
+  \end{block}
+  \begin{exampleblock}{Variations on ranges}
+    There are actually different type of ranges
+    \begin{itemize}
+    \item \mintinline{cpp}{input_range}, \mintinline{cpp}{output_range}, \mintinline{cpp}{forward_range}, \mintinline{cpp}{bidirectional_range}, \mintinline{cpp}{random_access_range}, \mintinline{cpp}{contiguous_range}
+    \item corresponding to the different iterator categories
+    \end{itemize}
+  \end{exampleblock}
+\end{frame}
+
+\begin{frame}[fragile]
+  \frametitlecpp[20]{Views}
+  \begin{block}{The view concept}
+    \begin{itemize}
+    \item A \mintinline{cpp}{view} is a non-owning object built from a range or another view after applying some range adaptor(s)
+    \item The time complexity to copy, move, assign is constant
+    \item Range adaptors can be applied/changed with \mintinline{cpp}{|} and are lazy
+    \item They live in the \mintinline{cpp}{std::views} namespace
+    \item They introduce easy functional programming to the STL
+    \end{itemize}
+  \end{block}
+  \begin{exampleblock}{Example}
+    { \scriptsize
+      \begin{cppcode*}{gobble=4}
+        auto const numbers = std::views::iota(0, 6);
+        auto even = [](int i) { return 0 == i % 2; };
+        auto square = [](int i) { return i * i; };
+        auto results = numbers | std::views::filter(even)
+                               | std::views::transform(square);
+        for (auto a : results) { ... } // 0, 4, 16
+      \end{cppcode*}
+    }
+  \end{exampleblock}  
+\end{frame}
+
+\begin{frame}[fragile]
+  \frametitlecpp[20]{Many range adaptors are provided by the STL}
+  \begin{block}{Useful subset}
+    \begin{description}[keys/values]
+    \item[all] a view on all elements
+    \item[filter] applies a filter
+    \item[transform] applies a transformation
+    \item[take] takes only first n elements
+    \item[drop] skips first n elements
+    \item[join/split] joins ranges or splits into subranges
+    \item[reverse] reverses view order
+    \item[elements] for tuple views, extract nth elements of each tuple
+    \item[keys/values] for pair like views, takes 1st/2nd element of each pair
+    \end{description}
+  \end{block}
+  Remember you can combine them via (\mintinline{cpp}{|})
+\end{frame}
+
+\begin{frame}[fragile]
+  \frametitlecpp[23]{Back to lazyness}
+  \begin{exampleblock}{\texttt{view}s are lazy}
+    \begin{itemize}
+    \item Computation is only trigerred when iterating
+    \item And can be stopped by e.g. \mintinline{cpp}{take}
+    \item Here the mininal number of iteration is performed
+    \end{itemize}
+    { \scriptsize
+      \begin{cppcode*}{gobble=2}
+        // print first 20 prime numbers above 1000000
+        for (int i: std::views::iota(1000000) | std::views::filter(odd) 
+                                              | std::views::filter(isPrime) 
+                                              | std::views::take(20)) {
+          std::cout << i << " ";  
+        }
+      \end{cppcode*}
+    }
+  \end{exampleblock}  
+\end{frame}

talk/setup.tex

@@ -23,10 +23,10 @@
 \defbeamertemplate*{headline}{mysplit theme}
 {%
   \leavevmode%
-  \begin{beamercolorbox}[wd=.45\paperwidth,ht=2.5ex,dp=1.125ex]{section in head/foot}%
+  \begin{beamercolorbox}[wd=.4\paperwidth,ht=2.5ex,dp=1.125ex]{section in head/foot}%
     \insertsectionnavigationhorizontal{.4\paperwidth}{\hskip0pt plus1filll}{}%
   \end{beamercolorbox}%
-  \begin{beamercolorbox}[wd=.55\paperwidth,ht=2.5ex,dp=1.125ex]{subsection in head/foot}%
+  \begin{beamercolorbox}[wd=.6\paperwidth,ht=2.5ex,dp=1.125ex]{subsection in head/foot}%
     \insertsubsectionnavigationhorizontal{.6\paperwidth}{}{\hskip0pt plus1filll}%
   \end{beamercolorbox}%
 }