if (NOT TARGET Catch2) project(Catch2 CXX) set(CMAKE_CXX_STANDARD 11) add_library(${PROJECT_NAME} INTERFACE) target_include_directories(${PROJECT_NAME} INTERFACE ${CMAKE_CU ${CMAKE_CURRENT_SOURCE_DIR}/include) # Mimic the library names in Catch2's own CMake files: add_library(Catch2::Catch2 ALIAS Catch2) # This one is historical, left over from when ApprovalTests.cpp cpp was first created. # We could encourage users to move away from it. add_library(catch2 ALIAS Catch2) endif ()

seen in C++ • Look at original goals/ideals of exception handling • Look at the mechanics of throw/catch • Look at Exceptions in both their use and design as seen in real code • Better thinking on the me{"Pete", 21}; apply(me); } catch (const MyStatus& s) { std::cout << "error : " << s << std::endl; } ... } } Error handling Happy Path (clean) Function signature changed } catch (...) { std::cout << Exception hygiene • Throw by value • Catch by (const) reference • Rethrow using throw with no arguments • Catch handlers with derived classes placed before catch handlers with base classes Exception

throw 5; } int main() { volatile int return_code = 0; try { return_code = start(); } catch (...) { return_code = -1; } return return_code; } 51Barrier #1 Exceptions disabled! 52☠ to convince you That was to show you that something is here. 94C++ Exceptions from throw to catch on GCC ARM 95Things that will NOT be covered here ● Nested exceptions ● Anything other than table based exceptions 96Consider the following 97 struct error {}; void foo() { try { bar(); } catch (error const& p_error) { // end up here... } } void bar() { destructible_t obj; baz();

to throw by value, catch by const ref, and re-throw using throw.• A fail-handling mechanism void bar() { try { foo(); } catch (error_type) { // do stuff, or re-throw; } catch (…) { // do stuff, responsibility 9• A fail-handling mechanism int main() { try { bar(); } catch (error_type) { // do stuff } // don’t catch; } “Re-delegate responsibility” PART 0: WHAT ARE EXCEPTIONS 10PART I: (expensive, un-deterministic mechanism) • C++ does not return tothe throwing code (but to the catch block). Exception handlers are rare compared to function definitions. The formal usage recommendation

try { g(); h(); } catch( std::exception const& ex ) { /* Handle exception */ } } Three keywords throw try catch Stack unwinding Objects on the stack are try { g(); h(); } catch( std::exception const& ex ) { /* Handle exception */ } } Three keywords throw try catch Stack unwinding Objects on the stack are try { g(); h(); } catch( std::exception const& ex ) { /* Handle exception */ } } Three keywords throw try catch Stack unwinding Objects on the stack are

ways to handle errors. One way is to use do-catch. Inside the do block, you mark code that can throw an error by writing try in front of it. Inside the catch block, the error is automatically given the printerResponse = try send(job: 1040, toPrinter: "Bi Sheng") 3 print(printerResponse) 4 } catch { 5 print(error) 6 } 7 // Prints "Job sent" E X P E R I M E N T Change the printer name send(job:toPrinter:) function throws an error. You can provide multiple catch blocks that handle specific errors. You write a pattern after catch just as you do after case in a switch. PDF conversion courtesy

callback: const fs = require('fs') try { const fd = fs.openSync('/Users/joe/test.txt', 'r') } catch (err) { console.error(err) } Once you get the file descriptor, in whatever way you choose ready: const fs = require('fs') try { const stats = fs.statSync('/Users/joe/test.txt') } catch (err) { console.error(err) } The file information is included in the stats variable. What isDirectory() // false stats.isSymbolicLink() // false stats.size // 1024000 //= 1MB } catch (err) { console.log(err) } } example() 35. Node File Paths Every file in the system

[=](id<1> i){ out[i] = inA[i] + inB[i]; }); }); gpuQueue.wait_and_throw(); } catch (sycl::exception &e) { /* handle SYCL exception */ } } 23 SYCL 2020 Hello WorldFirst we include [=](id<1> i){ out[i] = inA[i] + inB[i]; }); }); gpuQueue.wait_and_throw(); } catch (sycl::exception &e) { /* handle SYCL exception */ } } 24 SYCL 2020 Hello WorldIn this example [=](id<1> i){ out[i] = inA[i] + inB[i]; }); }); gpuQueue.wait_and_throw(); } catch (sycl::exception &e) { /* handle SYCL exception */ } } 25 SYCL 2020 Hello WorldIn SYCL all

overwritten before being used." In Debug mode, Zig writes 0xaa bytes to undefined memory. This is to catch bugs early, and to help detect use of undefined memory in a debugger. Variables A variable is a 123 a.? Optionals Equivalent to: a orelse unreachable const value: ?u3 value.? == 5678 a catch b a catch |err| b Error Unions If a is an error, returns b ("default value"), otherwise returns the unwrapped Precedence x() x[] x.y x.* x.? a!b x{} !x -x -%x ~x &x ?x * / % ** *% || + - ++ +% -% << >> & ^ | orelse catch == != < > <= >= and or = *= /= %= += -= <<= >>= &= ^= |= Arrays arrays.zig const expect = @import("std")

from: • Catch2, with a little bit of Qt Test • Tricks needed to use Qt with Catch2 – Useful if using different framework23 Setting up testsuite main() // Demonstrate how to create a Catch main() for #define CATCH_CONFIG_RUNNER #include <Catch.hpp> #include int main(int argc, char* argv[]) { QApplication app(argc, argv); // -platform offscreen int result = Catch::Session() test our stuff! ☜ ☜ ☜26 ColorWidget setup – QColor object #include "catch.hpp" #include "color_widget.hpp" #include "catch_qt_string_makers.hpp" using namespace ScIDE; TEST_CASE("ColorWidget initial