w w w . a t o m o s s p a c e . c o m Newer Isn’t Always Better Investigating Legacy Design Trends and Their Modern Replacements Katherine Rochaatomosspace.com | 3 • Software Engineer at Atomos Space can be used to access an element • Index can be used for in loop side effects/calculations • Doesn’t require a group of items • More dangerous access operations Original Trend – Index For Loopatomosspace vs Meyers’ Singletonatomosspace.com | 19 template T> class Singleton { public: static T& getInstance() { static T instance; return instance; } private: Singleton();

What Volatile Means (and Doesn't Mean) Copyright © 2024 by Ben Saks and Dan Saks 0-1 What Volatile Means (and Doesn’t Mean) by Ben Saks and Dan Saks September, 2024 1 Saks & Associates These notes +1-412-521-4117 (voice) service@saksandassociates.com saksandassociates.com 2What Volatile Means (and Doesn't Mean) Copyright © 2024 by Ben Saks and Dan Saks 0-2 Introduction  The volatilequalifier is a vital compilers from performing certain harmful optimizations.  Unfortunately, many C++ programmers aren’t clear on exactly what protections volatileprovides.  As such, many programmers apply the volatilequalifier

1Tracy: a profiler you don’t want to miss Marcos Slomp Senior Research Engineer IIWhy Tracy? Real-time workflow (analyze application while it is running) Precise measurements (nanosecond resolution) com/watch?v=dToaepIXW4s“C++ programmers talk all the time about efficiency, but they generally don’t know how to measure.” - Bjarne Stroustrup CppCon 2023 Keynote (literally three days ago!)Tracing change the zone name • can be non-persistent string (e.g., an std::string in the stack) • new name WON’T appear in profiler statistics! • ZoneColor • programmatically change the zone color Avoid! (it will

1Tracy: a profiler you don’t want to miss Marcos Slomp Senior Research Engineer IIWhy Tracy? Real-time workflow (analyze application while it is running) Precise measurements (nanosecond resolution) com/watch?v=dToaepIXW4s“C++ programmers talk all the time about efficiency, but they generally don’t know how to measure.” - Bjarne Stroustrup CppCon 2023 Opening Keynote (literally three days ago!)Tracing change the zone name • can be non-persistent string (e.g., an std::string in the stack) • new name WON’T appear in profiler statistics! • ZoneColor • programmatically change the zone color Avoid! (it will

Can’t we just synthesize std::tuple_element from get? Jonathan Müller — @foonathanAdding structured bindings support to a custom tuple-like type template T> struct my_tuple { … }; Jonathan Müller — @foonathan Can’t we just synthesize std::tuple_element from get? CppCon 2024-09-18 1Adding structured bindings support to a custom tuple-like type template T> struct my_tuple { … template t I, typename Tuple> requires instance_oft> auto get(Tuple&& t) -> decltype(auto) { … } Jonathan Müller — @foonathan Can’t we just synthesize std::tuple_element

compare_exchange is Daniel Anderson -- danielanderson.net4 Our motivating problem • Required by std::weak_ptr<T>::lock • Also, very useful for atomic memory management / concurrent data structures Daniel Anderson Otherwise return false. // Precondition: The counter is not zero bool decrement(); uint64_t read(); // Return the current value of the counter }; • Sometimes referred to as a “sticky counter” bool decrement() { return (--counter == 0); } uint64_t read() { return counter; } uint64_t counter{1}; }; Thread 1: increment_if_not_zero() if (counter > 0) {

Metafunction 13Return From a Metafunction • Expose a public value "value" 13 template T> struct TheAnswer { static constexpr int value = 42; };Return From "type" 13 template T> struct TheAnswer { static constexpr int value = 42; }; template T> struct Echo Echo { using type = T; };Value Metafunctions 14Value Metafunctions • Simple regular function: identity 14 int int_identity(int x) { return x;

create a template specialization 6 templateT1, class T2> struct pair { T1 first; T2 second; ... }; templateT> T const& max(T const& a, T const& b) { ... } pair my_pair; = ...; string s3 = max(s1, s2); templateT1, class T2> struct pair { T1 first; T2 second; ... }; templateT> T const& max(T const& a, T const& b) { ... } Recap: Templates and Specializations parameters • Syntax errors are discovered • Names that don't depend on template parameters are looked up • Static assertions that don't depend on template parameters are checked • At instantiation

CppCon 2024 Generic Programming Same code works on different, unrelated types T sum(C container) { T result = 0; for (T value : container) { result += value; } return result; }7 David Olsen – Generic CppCon 2024 Class Template Definition template T, class U> class pair { T m0; U m1; public: pair() { } pair(T v0, U v1) : m0(v0), m1(v1) { } T first() const { return m0; } U second() const { return CppCon 2024 Class Template Definition template T, class U> class pair { T m0; U m1; public: pair() { } pair(T v0, U v1) : m0(v0), m1(v1) { } T first() const { return m0; } U second() const { return