For a Microsoft event we have been hired to do a full-day workshop about news in Visual Studio 2012 for C++ developers. My colleague Philipp Aumayr conducted the workshop. Here are the slides for his talk. More details including sample code can be found in our developer blog at http://www.software-architects.com

1. Philipp Aumayr
software architects gmbh
Web http://www.timecockpit.com
Mail philipp@timecockpit.com
Visual C++ 2012 Twitter @paumayr
Improvements over 2008
Saves the day.

2. Intro
 DI Philipp Aumayr
 Senior Developer @ software architects (time cockpit)
 9-5 -> C#, 5->9 C++, 24/7 VS 2012
 Twitter: @paumayr
 Blog: http://www.timecockpit.com/devblog/

3. Motivation
 Visual Studio 2012 improvements over 2008
New Shell
New Editor
Better Intellisense
Unit Testing
Code Coverage
Code Analysis
#include completion
Navigate To
Type visualizers

4. Motivation
 C++11
New standard released August 12, 2011
Major overhaul
Bjarne Stroustrup: „C++11 feels like a new language“
Visual Studio 2012 has partial support
Is updated out-of-band (November CTP adds major language parts)
auto, decltype, range-based for loop
lambdas, explicit overrides, static_assert
nullptr, enum classes, move-semantics, variadic templates,
initializer_lists, delegating constructors,
explicit conversion operators

5. Motivation
 STL improvements
shared_ptr, unique_ptr
unordered_set, unordered_map
SCARY iterators + container sizes
 Move Semantics
 std::async
 Code Analysis
 SDL

6. Motivation
 Auto-vectorization
 Auto-parallelization
 C++ AMP
A lot to learn, but well worth the effort!

7. IDE Improvements
 Multi-monitor support
Rewritten in WPF and MEF
 Improved responsiveness
Intellisense works in the background
Asynchronous project loading
 Editor Zooming
 Navigate-To
 Call Hierarchy
 Demo

8. IDE Improvements
 Preview tab
 Pinned editor windows
 Ctrl + Q / Search Menu
 New Solution explorer
Scope to this
multiple views
 Find within editor
 Find all references
 Demo

9. Test Framework
 Supports writing unit tests for MSTest
Test adapters for other test frameworks are available
Gtest
xUnit++
 Test Explorer Window
Grouping
 Code Coverage
 Demo

10. Better Intellisense
 Uses an SDF (SQL CE database) instead of the ncb
 Faster
 More robust
 Demo

11. Type Visualizers (Natvis)
 Allow customizable data representation in debugger
Replaces autoexp.dat
Easier to handle, more powerful
 Create a natvis file
Place in either
%VSINSTALLDIR%Common7PackagesDebuggerVisualizers (requires admin access)
%USERPROFILE%My DocumentsVisual Studio 2012Visualizers
Or VS extension folders
 Files are reloaded at every debugging session
No restart required when changing natvis files

12. Type Visualizers (Natvis)
 Example natvis file
 Allows
conditional strings, node expansions, item lists, tree items, synthetic items, etc.

13. Break
New Editor
Better Intellisense
Unit Testing
Code Coverage
Code Analysis
#include completion
Navigate To
Type visualizers

14. Break
 Questions?

15. C++ Styles (Question)
C with a C++ compiler?
C with classes / inheritance?
 RAII, Exceptions, Smart pointer?
 STL?
 TMP?

16. auto
 Automatically deduces type information
Very similar to „var‟ in c#
Reduces amount of typing required
 Reference or Value?
Value by default, add & to make it a reference
 Demo

17. decltype
 Represents the type of the expression
decltype(2*3) -> int
decltype(a) -> type of a
 Why?
Let types flow!
 Demo

18. Range based for loop
 New type of for loop
 Iterates all members of a collection
 Demo

19. Lambdas
 Anonymous Functions
 Allows logic to be placed where required
 Can capture environment
 General syntax:
[capture](parameters)->return-type{body}
 represent by type std::function<>

20. Lambdas
 Finally make STL algorithms useable
 Reduces amount of (boilerplate-)code
No more functor classes!

21. Lambda Captures
 A Lambda can capture environment
Allows the lambda to access and modify state
 Capture kinds
- reference or value
- automatic or specific
 Demo

22. override and final
 Explicitly defines overrides
Compiler helps if no method to override is found
 Helps with refactoring
Rename method in base class but not in derived -> derived method no longer overrides
Base class from third party!
 Helps class design
Implementers of derived classes can more easily understand which methods to override
 final can be used on classes to prevent being derived from
 Demo

23. override and final

24. static_assert
 Tests a software assertion at compile time
 Especially useful for portable code
Assert size of specific structures (x86, x64 issues)
 Check library versions
 Used to be accomplished using the preprocessor
 Demo

25. nullptr
0 / NULL used to indicate a null pointer
 nullptr is of type nullptr_t
 implicitly assignable to any pointer
 not assignable to int etc.

26. enum classes
 C++03 enums
Not type safe
Enums of different types can be compared (basically integers)
Storage type int
 C++11 enum classes
Type is compared as well!
Underlying type can be chosen

27. enum classes
 C++03 enums

28. enum classes
 C++11 enum classes

29. Initializer lists (CTP)

30. Initializer lists (CTP)
 Eases construction of non-POD types
 Finalversion will provide initialize list constructors for
STL types
 Binds {…} syntax to the std::initializer_list<T> type.
 Current STL does not support it
 Demo name == “class std::initializer_list<int>”

31. variadic templates (CTP)
 Flexible number of template arguments
 Usable for template writers
n-ary structures (tuples)
e.g. make_shared, make_tuple
Example: saveprint
 Beware of dragons ;)
 Demo

32. Move Semantics
 C++03: many (temporary) class instances
Resulted in a lot of copying
Constructs to work around
Passing complex data structure from function
 C++11: Move semantics
If the copied value is an rvalue reference, the move constructor is called

33. Move Semantics
 Dramatically changes style!
C++03 C++11

34. Move Semantics
 Note: right-hand version is valid C++03 code!
But advanced programmers avoided it, due to the extra copy involved.
 Now with C++11: Elegant AND Fast
Reconsider the patterns you are used to
 All STL containers implement move semantics
Returning container was unavoidable? -> automatic performance improvement!
 STL code will have fewer temporary objects
 Demo

35. Break
 C++11
auto, decltype, range-based for loop
lambdas, explicit overrides, static_assert
nullptr, variadic templates,
initializer_lists, enum classes,
move-semantics

36. std::async
 C++ 11 has built-in support for asynchrony
available through <future> header
 std::async<T>(std::function) returns a future<T>
- Different launch policies (synchronous, asynchronous)
- can be waited on using wait() or get() to retrieve the result
 Implemented in VC++ using PPL (parallel patterns
library)
- Highly scalable and performant

37. std::async
 Not
every asynchronous operation is a thread / cpu
bound
Notably IO requests
User Input etc.
 std::future<T> can be created from a std::promise<T>!
 std::promise<T> acts as a provider for a future
Marshalls result between threads of execution
correct locking / etc.
Provides set_value / set_exception

38. std::async
T1 T2
(Blocks)
Demo

39. Parallel Patterns Library
 Based on ConcRT
 Compatible to Intel Thread Building Blocks (TBB)
At least interface wise
 Template Library for parallel programming
Abstracts concurrent workflows into tasks
Provides continuations (improvement over std::future<T>)
 Demo

40. Auto Vectorization
 Modern CPUs support SIMD
Single Instruction Multiple Data
Extensions such as SSE and AVX
Usually optimized for specifically using compiler intrinsics or inline assembler
Serial Vector
x = x1 + x2 xyzw = xyzw1 + xyzw2
y = y1 + y2
z = z1 + z2
w = w1 + w2
τ

41. Auto Vectorization
 VC++ 2012 compiler has an auto-vectorizer (-Qvec)
Tries to automatically vectorize loops and operators
Enabled by default
Diagnosis output using /Qvec-report:2
 Performance difference?
Depends.
Max 4x for SSE (128bit), 8x for AVX (256bit),
3x-4x typical
 Demo (later with auto parallelization)

42. Auto-Parallelization
 To utilize multiple cores, parallelization is used (MIMD)
Multiple-Instructions-Multiple-Data
 VC++2012 has an auto-parallelizer
Can be hinted
#pragma loop(hint_parallel(N))
#pragma loop(ivdep)
Enabled using /Qpar
Diagnosis using /Qpar-report:2
 Demo

43. C++ AMP
 Open specification created by Microsoft
 C++ for GPGPU
Massively Parallel / Vector programming
Based on top of DirectCompute (windows)
Clang / LLVM implementation using OpenCL is available
Provided by Intel (“Shevlin Park”)
 One new keyword
Restricts the decorated function to a specific subset of c++
 Template library for wrapping data structures
Datatransfer to/from GPU etc.

44. Why C++ AMP?
 Directly available from the compiler
No additional SDK required
Can reuse types (vector2f e.g.)
 Better debugging experience
compared to CUDA / OpenCL!
 Makes C++ applicable to heterogeneous computing
A processor may consist of multiple cores of different flavor
More energy efficient (mobile!)
visual computing
image morphing
Augmented reality etc.
 Demo

45. Smaller container sizes
 X86 release, sizes in bytes
Container VC9 SP1 / SCL = 0 VC10 (2010) VC11 (2012)
(2008)
vector<int> 16 16 12
deque<int> 32 24 20
forward_list<int> N/A 8 4
queue<int> 32 24 20
stack<int> 32 24 20
unordered_map<int, int> 44 44 32
string 28 28 24
wstring 28 28 24 ~14% less!

46. Smaller container sizes
 x64 release, sizes in bytes
Container VC9 SP1 / SCL = 0 VC10 (2010) VC11 (2012)
(2008)
vector<int> 32 32 24
deque<int> 64 48 40
forward_list<int> N/A 16 8
queue<int> 64 48 40
stack<int> 64 48 40
unordered_map<int, int> 88 88 64
string 40 40 32
wstring 40 40 32 ~20% less!

47. Code Analysis
 Static analysis
 Provides warnings at compile time
 Additionally to /GS and /SDL
 Detailed information on warning

48. Code Analysis
 What does it check ?
Uninitialized Reads
HRESULT verification checks
Concurrency Warnings
Format string checks
Correct destructor calls (delete[] vs delete)
Redundant code checks
Many more: http://msdn.microsoft.com/en-us/library/a5b9aa09.aspx
 Custom code can be annotated to aid code analysis
See http://msdn.microsoft.com/en-us/library/ms182032.aspx
 Demo

49. Break
 std::async
 ppl
 auto vectorization
 auto parallelization
 container sizes
 code analysis

50. Custom Snippets
 .snippet is supported, same as C#
XML file describing a code snippet
Declare variables and use them in the snippet body
 Very helpful for similar but not equivalent code
 Demo

51. Debug View
 Pin watch to source code
Add comments
Not only variables, but (most) expressions
 View values from last debug session
 Export / Import Data Tips
Makes it easier for debugging with multiple developers / on different machines
 Demo

52. Parallel Stacks Window
 New view for debugging
 Better understanding of multi thread applications

53. Parallel Tasks Window
 Lists the task queues

54. Parallel Watch Window
 Watch expressions in parallel
Especially useful in tight loops
Data races Expressions
Can freeze / thaw threads
Manually verify locking
 Demo
Parallel Stacks
Parallel Tasks
Threads
Parallel Watch

55. Shortcuts
Shortcut Action Shortcut
Strg + , Navigate To Strg + Q Search Menu
F12 Go To Definition Strg + K, C Comment lines
Umschalt + F12 Find all references Strg + K, U Uncomment lines
Strg + - Navigate Backwards Strg + M, O Collapse To definition
Strg + Umschalt + - Navigate Forwards Strg +M, X Expand All Outlining
Strg + F Find in current file Strg +M, S Collapse Current Region
Strg + H Replace in current file Strg + M, E Expand Current Region

56. Break
 Custom snippets
 Debug view experience
 Parallel Stacks
 Parallel Tasks
 Parallel Watch Window
 code analysis
 Shortcuts

57. What‟s next?
 It‟s a good century for C++ / native developers
Single thread performance isn‟t getting much better
memory latency / bandwidth is the bottleneck
Efficiency is becoming more important (mobile!)
 There is a huge commitment towards C++
Google, Apple started a new compiler project a few years ago (Clang / LLVM)
ISO standard is evolving more quickly
C++ Standards Foundation (www.isocpp.org)
Google, Apple, Intel, Microsoft, ARM, IBM, HP, etc.

58. Upcoming Standards
 Library in std:: for file system handling
based on boost.filesystem v3
We are here!
 Net TS
Networking
HTTP etc.
 TM TS
Transactional Memory

59. Wrap-Up
 Tour around the new IDE  New Library Features
Shell / Window handling std::async
Solution Explorer PPL
Code Navigation Improved container sizes
Better Intellisense
Snippets, Debug Experience
Parallel Watch, Threads, Tasks
 New Compiler Features
 New Language Features Code Analysis
auto, decltype, lambdas,
/SDL /GS
override, final
Auto Vectorization
static_assert, nullptr
Auto parallelization
C++ AMP

60. Philipp Aumayr
software architects gmbh
Q&A Mail philipp@timecockpit.com
Web http://www.timecockpit.com
Twitter @paumayr
Thank your for coming!
Saves the day.