requires expression Concept (named requirements) // OK, uses 1st add() calling push_back() // OK, uses 2nd add() calling insert() Nico Josuttis C++ Concepts @cppcon 2024-09-18 3©2024 by josuttis.com 7 C++ coll2; add(coll1, 42); // OK, uses 1st add() calling push_back() add(coll2, 42); // OK, uses 2nd add() calling insert() C++20 C++20 Type Constraints with concepts applied to types Requirements 42); add(coll2, 42); // C++20 C++20 // ERROR: "can't call insert()" // OK, uses 2nd add() calling insert() 2nd add() is used, because concept for 1st add() not satisfied Requirements not met =>

sorting with the Sorter interface .......................................................277 11.8 2nd example: Reading and Writing .....................................................................282 installation) $GOARCH the processor-architecture of the target machine, one of the values of the 2nd column of fig 2.1: 386, amd64, arm. $GOOS the operating system of the target machine, one of Example: strings.Trim(s, “\r\n”) removes all leading and trailing \r and \n from the string s. The 2nd string-parameter can contain any characters, which are all removed from the left and right-side of

eax, edi shl eax, 4 add eax, esi ret ... Flush, update branch history, refetchExample – branching, 2nd attempt 72 uint32_t fn(uint32_t x, uint32_t y, size_t cond) { if (cond == 27) return (x << 4) 89 F8 C1 E0 04 01 F0 EB 06 89 F8 D1 E8 29 F0 C3 66 66 0F 1F 84 00 00 00 00 00Example – branching, 2nd attempt 73 uint32_t fn(uint32_t x, uint32_t y, size_t cond) { if (cond == 27) return (x << 4) 89 F8 C1 E0 04 01 F0 EB 06 89 F8 D1 E8 29 F0 C3 66 66 0F 1F 84 00 00 00 00 00Example – branching, 2nd attempt 74 uint32_t fn(uint32_t x, uint32_t y, size_t cond) { if (cond == 27) return (x << 4)

scripts twice. There are 3 check points: 1. Import fresh module without __pycache__ 2. Import module 2nd with __pycache__ 3. Run function "foo", an obfuscated class is called 10,000 times Here are test steps: (ms) Import fresh module Import module 2nd Run function “foo” Python Origin Pyarmor Origin Pyarmor Origin Pyarmor Time (ms) Import fresh module Import module 2nd Run function “foo” Python Origin Pyarmor Import module 2nd Run function “foo” Python Origin BCC Mode Origin BCC Mode Origin BCC Mode 3.7 1.130 327.906 1.000 283.469 325.828 283.972 Time (ms) Import fresh module Import module 2nd Run function

the 2nd function: f(1.1, 2, 3); // calls f(double, int, double)  The conversions are the same for both functions on the 1st and 3rd arguments.  The 2nd function is a better match on the 2nd (middle)

scripts twice. There are 3 check points: 1. Import fresh module without __pycache__ 2. Import module 2nd with __pycache__ 3. Run function "foo", an obfuscated class is called 10,000 times Here are test steps: (ms) Import fresh module Import module 2nd Run function “foo” Python Origin Pyarmor Origin Pyarmor Origin Pyarmor Time (ms) Import fresh module Import module 2nd Run function “foo” Python Origin Pyarmor Import module 2nd Run function “foo” Python Origin BCC Mode Origin BCC Mode Origin BCC Mode 3.7 1.086 1.177 0.342 0.391 344.640 271.426 Time (ms) Import fresh module Import module 2nd Run function “foo”

Object-Oriented Software Construction (2nd ed.)Meyer OPC: Adapting a Module to New Clients (After) Meyer, B. (1997). Object-Oriented Software Construction (2nd ed.)OCP in C++: Strong and Weak Principles

<< '\n'; } // print every 2nd element (array, vector, deque only): for (auto pos = coll.begin(); pos < coll.end(); pos += 2) { std::cout << *pos << '\n'; } // print every 2nd element (for all containers):

user group Chair of the CppCon Back-to-Basics track Email: klaus.iglberger@gmx.deThe 2nd in a Row 3The 2nd in a Row 45 Let’s again talk about design patterns and virtual functionsThe Overhead