together to ensure thorough software quality and reliability.Static Vs Runtime Runtime Static Compile timeStatic vs Runtime – Bounds Check Potential out of bounds write void foo(){ std::vector report_error(error); } }Runtime Error Reporting Runtime error reporting can be used with compile-time error detection void foo(){ constexpr auto error = detect_error(); if constexpr (error) static_assert(!error, "error message"); }Error Message We want to generate custom error messages at compile-time to provide better diagnostics struct custom_error {}; void foo() { constexpr auto error

Go compile time instrumentation Przemysław Delewski February 18, 2025 Warsaw, PolandAgenda 1. Short bio 2. Observability domain 3. OpenTelemetry 4. History of OpenTelemetry go compile time instrumentation also founding member of the OpenTelemetry Go compile-time instrumentation project https://github.com/open-telemetry/community/blo b/main/projects/go-compile-instrumentation.mdSoftware complexity Today's https://github.com/open-telemetry/opentelemetry-go-compile-instrumentation/ Blog post https://opentelemetry.io/blog/2025/go-compile-time-instrumentation/Thank you! Go compile time instrumentation Przemysław Delewski

participate in game jams. • Enjoy experimenting, exploring, and trying new things in C++.Dive Into Compile-Time Parsers Libraries Use Cases Implementation Techniques Reflection Language Evolution Operator overloading • Domain specific languages • Open source compile-time libraries • API • Design • Implementation details • Using compile-time parsers • Reflection • Examples: functions, types, treesParser = parser("SELECT id, name WHERE age > 42"); std::vector result = func(cats);Example – Compile Time Parsers std::vector cats = { /*...*/ }; constexpr auto parser = create_parser(); constexpr

Stephen Brawner, Robottimo Robotics at Compile Time Optimizing Robotics Algorithms with c++’s Compile-Time FeaturesAbout me • Robotics Software Consultant based in Portland, OR • Chief Roboticist };• With explicit classes and runtime dispatch • https://godbolt.org/z/9YMP3aqs5 • With better compile-time dispatch • https://godbolt.org/z/fKd9h4ofdHandling Joint Limits template Compile Time bool is_in_collision( const BoxWithPose& shape1, const SphereWithPose& shape2){...} …

/ 1/ Introduction Explore how C++20's constexper features can: Generate data from code at compile-time Be used to construct: Lookup Tables Con�guration Fuses Compressed Strings USB Descriptors 2 found building compile-time libraries 2 . 2/ constexpr in Brief Speci�es a variable or function CAN appear in a constant expression Constant expressions can be evaluated at compile-time eg: Array MUST produce a compile-time constant Implies constexpr 4/ constinit Speci�es a variable has static initialization constant initialised (from a constant expression) computed at compile-time, and stored

Apex.AI, Inc. Errors have a high cost, so rigorous testing is a must We use increasingly more compile-time polymorphism and checks Question: how to test if something is compilable in a rigorous way EXPECT_FLOAT_EQ(21.0F, get_half_of(42.0F)); EXPECT_DOUBLE_EQ(21.0, get_half_of(42.0)); // This should NOT compile: // get_half_of(23); }© 2021 Apex.AI, Inc. Now throw it into the rest of the code base ██████ EXPECT_FLOAT_EQ(21.0F, get_half_of(42.0F)); EXPECT_DOUBLE_EQ(21.0, get_half_of(42.0)); // This should NOT compile: // get_half_of(23); }© 2021 Apex.AI, Inc. And deliver it to the customers image: Flaticon.com

THE COMPILER... 3 . 2WHY JIT-COMPILE? WHY JIT-COMPILE? 3 . 3WHY JIT-COMPILE? WHY JIT-COMPILE? AOT IS NOT POSSIBLE AOT IS NOT POSSIBLE 3 . 3WHY JIT-COMPILE? WHY JIT-COMPILE? AOT IS NOT POSSIBLE AOT IS 3WHY JIT-COMPILE? WHY JIT-COMPILE? AOT IS NOT POSSIBLE AOT IS NOT POSSIBLE AOT IS NOT DESIRABLE AOT IS NOT DESIRABLE JIT GIVES PERF BENEFITS JIT GIVES PERF BENEFITS 3 . 3WHY JIT-COMPILE? WHY JIT-COMPILE JIT-COMPILE? AOT IS NOT POSSIBLE AOT IS NOT POSSIBLE AOT IS NOT DESIRABLE AOT IS NOT DESIRABLE JIT GIVES PERF BENEFITS JIT GIVES PERF BENEFITS JIT GIVES PRODUCTIVITY BENEFITS JIT GIVES PRODUCTIVITY BENEFITS

behavior occurs, the compiler catches it. However, once an integer value is no longer known at compile-time, it must have a known size, and is vulnerable to undefined behavior. fn divide(a: i32, b: i32) have to separate code into two object files - otherwise the optimizer figures out all the values at compile-time, which operates in strict mode. float_mode.zig const warn = @import("std").debug.warn; extern by Zero for integers. Can cause Division by Zero for floats in FloatMode.Optimized Mode. For non-compile- time-known signed integers, must use @divTrunc, @divFloor, or @divExact instead of /. 10 / 5 ==

behavior occurs, the compiler catches it. However, once an integer value is no longer known at compile-time, it must have a known size, and is vulnerable to undefined behavior. fn divide(a: i32, b: i32) have to separate code into two object files - otherwise the optimizer figures out all the values at compile-time, which operates in strict mode. $ zig build-obj foo.zig --release-fast $ zig build-exe test integers. Can cause division by zero for floats in 10 / 5 == 2 FloatMode.Optimized Mode. For non-compile- time-known signed integers, must use @divTrunc, @divFloor, or @divExact instead of /. a % b a

}; } }; Doc comments are only allowed in certain places; eventually, it will become a compile error have a doc comment in an unexpected place, such as in the middle of an expression, or just behavior occurs, the compiler catches it. However, once an integer value is no longer known at compile-time, it must have a known size, and is vulnerable to undefined behavior. fn divide(a: i32, b: i32) have to separate code into two object files - otherwise the optimizer figures out all the values at compile-time, which operates in strict mode. float_mode.zig const warn = @import("std").debug.warn; extern