designed ones!When talking about performance, we typically think about the function logic. We’ll see that a well designed function API can have an even larger impact.How will we compare performance? ● they might be, and often are, totally irrelevant to speed. 17 Credit to Khalil Estell: Firefox function distribution 157946 functions above (127B) 167404 functions below (127B)Understanding how machine problems? Pros: ● Default constructor before the function call is avoided 36Does it solve our problems? Pros: ● Default constructor before the function call is avoided Cons (unless we fully trust the

Back to Basics - Function Call Resolution Copyright © 2024 by Ben Saks and Dan Saks Back to Basics: Function Call Resolution by Ben Saks and Dan Saks September, 2024 1 Saks & Associates These notes +1-412-521-4117 (voice) service@saksandassociates.com saksandassociates.com 2Back to Basics - Function Call Resolution Copyright © 2024 by Ben Saks and Dan Saks About Ben Saks Ben Saks is the chief Ben earned a B.A. with Distinction in Computer Science from Carleton College. 4Back to Basics - Function Call Resolution Copyright © 2024 by Ben Saks and Dan Saks About Dan Saks Dan Saks is the president

Limitations and Problems in std::function and similar constructs Amandeep Chawla | Sr. Computer Scientist II amandeep@adobe.com | adchawla@gmail.com Image by Bruno Tornielli© 2024 Adobe. All Rights we can control. ▪ std::function© 2024 Adobe. All Rights Reserved. Adobe Confidential. Task Based Mechanism© 2024 Adobe. All Rights Reserved. Adobe Confidential. std::function ▪ Is a class template ▪ It is a general-purpose polymorphic function wrapper ▪ Instances of std::function can store, copy, and invoke any CopyConstructible Callable target ▪ Uses type-erasure under the hood to gain all the

outer_function (); }16/55 A mental model for coroutines: Cooperative Threads void spawn_task () { // ... Result r = outer_function (); } Result outer_function () { PartialResult r = middle_function (); PartialResult middle_function () { auto r = inner_function (); return PartialResult :: from_io_result (r); }16/55 A mental model for coroutines: Cooperative Threads PartialResult middle_function () { auto r r = inner_function (); return PartialResult :: from_io_result (r); } IoResult inner_function () { auto data = blocking_io (...); // this could take some time return IoResult :: from_io_data (data );

functions! We'll start with a basic function example, identifying the function signature and basic abilities of a function. Then we are going to view this function again from the perspective of assembly assembly (using compiler explorer) to show you how a function is structured. From the assembly view, we will then observe that functions have addresses (they must after all!) and that we can store functions pointers. We'll take a brief aside to show you how modern C++ also gives us the convenient std::function. Functions need not always be 'global' building blocks of our programs, the next step in our journey

C++ Automatic function / type deduction 7 . 2Copyright Jason Turner @le�icus emptycrate.com/idocpp ChaiScript Header-only scripting engine designed for embedding in C++ Automatic function / type deduction script function <-> C++ Function interaction 7 . 2Copyright Jason Turner @le�icus emptycrate.com/idocpp ChaiScript Header-only scripting engine designed for embedding in C++ Automatic function / type type deduction Native script function <-> C++ Function interaction Full support for exceptions 7 . 2Copyright Jason Turner @le�icus emptycrate.com/idocpp ChaiScript Header-only scripting engine designed

response->path = response_path; }Conventional Approach ● response is an out parameter that is set in the function void generate_path_service( const std::shared_ptr request response->path = response_path; }Conventional Approach ● response is an out parameter that is set in the function ● Error handling is done both by printing to logs and returning an error code via the service parameter that is set in the function ● Error handling is done both by printing to logs and returning an error code via the service response ● generate_global_path is the function that generates the path

Conditional function body constexpr everything Disable Cuda warnings host device template 3 The dark path Function dispatch triple 4 Cuda proposal Conditional host device Forbid bad cross function calls Cuda proposal Thank you Allowed function calls in Cuda CPU host GPU global device9/66 Motivation Patterns The dark path Cuda proposal Thank you Allowed function calls in Cuda CPU host GPU global Quiz time12/66 Motivation Patterns The dark path Cuda proposal Thank you Quiz time: Bad cross function calls � � 1 struct H { __host__ int func() { return 42; } }; 2 3 struct D { __device__ int func()

Principle (SRP); … is a factory function.7 std::make_unique() … … improves exception safety; … fulfills the Single-Responsibility Principle (SRP); … is a factory function.8 Possible order of operations: Principle (SRP); … is a factory function.16 std::make_unique() … … improves exception safety; … fulfills the Single-Responsibility Principle (SRP); … is a factory function.1718 “Everything should do factory function.27 std::make_unique() … … improves exception safety; … fulfills the Single-Responsibility Principle (SRP); … is a factory function.28 Core Guideline C.50: Use a factory function if

20);Callable Function Function Overloading Function Object Lambda Expression CoroutineCallable Function Function Overloading Function Object Lambda Expression CoroutineFunction A function is a sequence packaged as a unit. ▪ Implementation ▪ Each function call creates a stack frame on a stack data structure ▪ The stack frame contains the private data of the function call (parameters, locals and the return return address) ▪ At the end of the function, the stack frame is deleted Function in mathematic != Function in programmingPure Function Pure Function (Mathematical function) ▪ Produce the same result when