Day 3 of C++ Boot Camp - C++11 Language Deep Dive

Day 3 of C++ Boot Camp - C++11 Language Deep Dive

• 1.
  David Millington, Bruneau Babet, Patrick Scheller [email protected] Day 3: 
 Underthe hood of the 
 C++Builder IDE and Compilers
• 2.
  David Millington [email protected] Day 3: 
 C++11Language Deep Dive
• 3.
  Iterators it = collection.begin(); Loop until not equal to end() – end() points to one past the last item. Increment (eg ++ to inc by one) or decrement to move where in the range the iterator is pointing to. for (std::vector<int>::const_iterator it = 
 items.begin(); it != items.end(); it++) Pointer semantics: ‘dereference’ with * or ->, like a real pointer to something. int i = *it; // where it is an iterator in to a collection of ints
• 4.
  Lambdas Anonymous functions, written inline, capture variables, behave like objects (can assign to a variable.) [] The variable or capture list () The argument list {}Code [n](int& i, this) { return i + n == this->foo; }
• 5.
  Lambdas auto f =[&n](int i) { return i + n }; Making the simplest lambda [](){} a method that captures nothing, is passed no arguments, and does nothing. • Neat and readable • Inline in code • Inlineable and performant • Capture variables by value or reference • Behave like an object
• 6.
  Smart Pointers No: Foo* foo= new Foo(); __try { // } __finally { delete foo; } Yes: { unique_ptr<Foo> foo( new Foo()); } ^- foo is freed
• 7.
  Smart Pointers Using boost? Move to shared_ptr (very familiar!) and unique_ptr instead of scoped_ptr In general, already using them or not: • Use unique_ptr where possible •Use shared_ptr not out of ease but when you want to share • Don’t expect automatic threadsafety apart from +/- refcount • Use shared_ptr<Foo> p = make_shared<Foo>; and make_unique<T> if available - http://stackoverflow.com/questions/17902405/ how-to-implement-make-unique-function-in-c11 • Never write new or delete
• 8.
  Old vs Newstd::vector<int> items; items.push_back(1); items.push_back(2); items.push_back(5); std::map<int, std::wstring> map; map[1] = L"One"; map[2] = L"Two"; map[3] = L"Three"; // Demonstrate an algorithm for_each(items.begin(), items.end(), VectorMapFunctor(map)); // Print all vector items for (std::vector<int>::const_iterator it = items.begin(); it != items.end(); it++) { std::wcout << *it << std::endl; } // Create and do something with a Foo, then destroy it Foo* foo = new Foo(); Test(foo); delete foo; std::vector<int> items {1, 2, 5}; std::map<int, std::wstring> map { {1, L"One"}, {2, L"Two"}, {3, L"Three"} }; // Demonstrate an algorithm - now use a lambda for_each(items.begin(), items.end(), [&map](int n) { std::wcout << map[n] << std::endl; }); // Print all vector items for (auto i : items) { std::wcout << i << std::endl; } // Create and do something with a Foo, then destroy it std::unique_ptr<Foo> foo(new Foo()); Test(*foo); Definition not included –
 too much code already
• 9.
  Example extensions class Foo{ private: int m_Bar; void SetBar(int i) { m_Bar = i); public: __property Bar { read = m_Bar, write = SetBar } } Also closures (object instance + method pointer); RTTI; etc.
• 10.
  Compilers Classic: • bcc32, descendant of Turbo C++, Win32/OSX New / Clang enhanced: • Based on Clang, with extensions •Started with Clang 3.1 & Win64, now 3.3 with many backports, next 3.9 • Win32, Win64, iOS32/64 (ARM), Android ARM, Linux (x64, next release)… Free: • The Clang Win32 compiler • https://www.embarcadero.com/free-tools/ccompiler
• 11.
  Q&A and Resources– C++ talk next up! • Basics: Books! http://stackoverflow.com/questions/388242/the-definitive-c-book-guide-and-list and forums like the C ++ G+ group: https://plus.google.com/u/0/communities/116007775542700637383 (general C++) or https:// plus.google.com/communities/118315259185736124693 (C++Builder) • C++ / STL: http://cppreference.com • Auto: http://thbecker.net/articles/auto_and_decltype/section_01.html • Lambdas: http://www.drdobbs.com/cpp/lambdas-in-c11/240168241 • Smart pointers: http://www.acodersjourney.com/2016/05/top-10-dumb-mistakes-avoid-c-11-smart-pointers/ • C++ Builder • http://docwiki.embarcadero.com/RADStudio/Berlin/en/C++11_Language_Features_Compliance_Status • http://docwiki.embarcadero.com/RADStudio/Berlin/en/C++11_Features_Supported_by_RAD_Studio_Clang- enhanced_C++_Compilers https://www.facebook.com/cppbuilder and https://twitter.com/EmbarcaderoTech Under the hood of the C++ compiler and IDE: a conversation with Patrick Scheller and Bruneau Babet is up next, right after the Q&A!