tiny fixes found along the way on third day of advanced course

Author: Sebastien Ponce

talk/concurrency/threadsasync.tex

@@ -1,7 +1,7 @@
 \subsection[thr]{Threads and async}
 
 \begin{frame}[fragile]
-  \frametitlecpp[11]{Basic concurrency}
+  \frametitle{Basic concurrency \hfill \cpp11/\cpp20}
   \begin{block}{Threading}
     \begin{itemize}
     \item \cpp11 added \mintinline{cpp}{std::thread} in \mintinline{cpp}{<thread>} header

talk/expert/perfectforwarding.tex

@@ -167,8 +167,8 @@
       f(4);            // rvalue -> T&& is int&&
       double d = 3.14;
       f(d);            // lvalue -> T&& is double&
-      float f() {...}
-      f(f());          // rvalue -> T&& is float&&
+      float g() {...}
+      f(g());          // rvalue -> T&& is float&&
       std::string s = "hello";
       f(s);            // lvalue -> T&& is std::string&
       f(std::move(s)); // rvalue -> T&& is std::string&&

talk/expert/variadictemplate.tex

@@ -82,11 +82,11 @@
   \begin{exampleblock}{Example}
     \begin{cppcode*}{}
       template<typename... Args>
-      T sum1(Args... args) {
+      auto sum1(Args... args) {
         return (args + ...);     // unary fold over +
       }                          // parentheses mandatory
       template<typename... Args>
-      T sum2(Args... args) {
+      auto sum2(Args... args) {
         return (args + ... + 0); // binary fold over +
       }                          // parentheses mandatory
       int sum = sum1(); // error