## +23 ## Undefined Behavior: What Every Programmer Should Know and Fear ## FEDOR PIKUS ## 20 23 October 01 - 06 ## We will learn: ## • What is Undefined Behavior - And what it is not UB vs implementation-defined implementation-defined behavior vs unspecified behavior • Why have UB in programming languages? • How is UB related to performance? • UB and C++ compilers • How to avoid UB? • How to take advantage of programs? ## What is Undefined Behavior (UB) in C++? • The concept is defined in the standard int f(int k) { • According to the standard, if k > INT_MAX-10, the result is undefined – “The program is

University. Title: Behavior-driven Tests for Microservices-based Algo Trading System ## Summary: Introduction: This poster will introduce a test framework we use at Bloomberg to enable behavior-based tests points: - End-to-end: The test framework validates the end (client) to end (broker/exchange) also behavior. - Controlled external dependencies: All external dependencies including market data, reference

7d3437878d5b9a4de6/p20_1.jpg) ## Undefined Behavior! This is  ## Erroneous behavior for unitialized reads P2795R5 (C++26) initialized int a; // not initialized int b{a}; // ?? int a; // not initialized int b{a}; // undefined behavior auto double_in_place(int& v) { v *= 2; } Elementary Form: Programming Compiler This is  ## Undefined Behavior! Is C++ safe? Modern C++: # Effective reference syntax Modern C++ 42 SPECIFIC WAYS TO IMPROVE

Virtual Agents ## DAVIDE FACONTI ## 20 23 October 01 - 06 ## What you will learn today 1. What Behavior Trees are 2. About the C++ library BehaviorTree.CPP ## About me • Davide Faconti, nice to meet b662e9d441565a9dd326035c73ae34/p3_1.jpg) ## How did I end up developing a Behavior Tree Library? Emergency stop ## Behavior Trees in the Game Industry  ## The role of Behavior Trees in robotics In the last 20 years, the de-facto standard in robotics has been (informally)

means that all unittests pass on the new version, but there might still be small bugs in there and behavior might be inconsistent. If you notice any bugs, please provide feedback in the Jinja bug tracker Modifications on environments after the first template was loaded will lead to surprising effects and undefined behavior. Here are the possible initialization parameters: block_start_string The string marking the optimized should the optimizer be enabled? Default is True. undefined Undefined or a subclass of it that is used to represent undefined values in the template. Finalize A callable that can be used to

an open-source programming language designed for robustness, optimality, and clarity. • Robust - behavior is correct even for edge cases such as out of memory. • Optimal - write programs the best way they - Escape Sequences - Multiline String Literals - Assignment - undefined - Variables - Global Variables - Thread Local Variables - Local Variables - Integers Implicit Cast: unions and enums - Implicit Cast: Zero Bit Types - Implicit Cast: undefined ☐ Explicit Casts ☐ Peer Type Resolution ## • Zero Bit Types ○ void • Pointers to Zero Bit

general-purpose programming language designed for robustness, optimality, and maintainability. • Robust - behavior is correct even for edge cases such as out of memory. • Optimal - write programs the best way they Character Literals - Escape Sequences - Multiline String Literals - Assignment - undefined - Variables - Global Variables - Thread Local Variables - Local Variables - Integers Known Numbers ■ Implicit Cast: unions and enums ■ Implicit Cast: Zero Bit Types ■ Implicit Cast: undefined ☐ Explicit Casts ☐ Peer Type Resolution • Zero Bit Types void Pointers to Zero

programming language and toolchain for maintaining robust, optimal, and reusable software. • Robust - behavior is correct even for edge cases such as out of memory. • Optimal - write programs the best way they false|bool values| |null|used to set an optional type to null| |undefined|used to leave a value unspecified| See also: • Optionals • undefined ## String Literals and Character Literals String literals i32; ## undefined Use undefined to leave variables uninitialized: ### test.zig const assert = @import("std").debug.assert; test "init with undefined" { var x: i32 = undefined; x

programming language and toolchain for maintaining robust, optimal, and reusable software. • Robust - behavior is correct even for edge cases such as out of memory. • Optimal - write programs the best way they false|bool values| |null|used to set an optional type to null| |undefined|used to leave a value unspecified| See also: • Optionals • undefined ## String Literals and Unicode Code Point Literals String i32; ## undefined Use undefined to leave variables uninitialized: test.zig const expect = @import("std").testing.expect; test "init with undefined" { var x: i32 = undefined; x

programming language and toolchain for maintaining robust, optimal, and reusable software. ## Robust Behavior is correct even for edge cases such as out of memory. ## Optimal Write programs the best way they false|bool values| |null|used to set an optional type to null| |undefined|used to leave a value unspecified| See also: • Optionals • undefined ## String Literals and Unicode Code Point Literals String i32; ## undefined Use undefined to leave variables uninitialized: assign_undefined.zig 1 const print = @import("std").debug.print; 2 pub fn main() void { 4 var x: i32 = undefined; 5 x