Visual Studio 2015 CTP fixed bugs and known issues

• The workarounds about the new CLR JIT compiler in the Visual Studio "14" CTP 4 (version 14.0.22129.1.DP) details section of this KB do not work with CTP 6. The ability to use the legacy JIT will be restored in the next public update of Visual Studio 2015.

• Upgrading from a localized version of Visual Studio 2015 Preview to Visual Studio 2015 CTP will revert to English only resources
  
  Visual Studio 2015 Preview is released in 10 languages fully localized. They include English, Chinese Simplified, Chinese Traditional, French, German, Italian, Japanese, Korean, Russian, and Spanish. Additionally, Visual Studio 2015 preview Languages Packs are released in 14 languages. They include English, Chinese Simplified, Chinese Traditional, French, German, Italian, Japanese, Korean, Russian, Spanish, Brazilian Portuguese, Czech, Polish, and Turkish.
  
  Visual Studio 2015 CTP will be released for the English language only. When you upgrade from a localized non-English version of Visual Studio 2015 Preview to Visual Studio 2015 CTP, all resources and user interface will revert to English.
  
  Therefore, when a newer Visual Studio 2015 Ultimate CTP5 is installed, the older Visual Studio 2015 Ultimate Preview (of any localized language) will be removed. All old Visual Studio 2015 Preview resources will be removed leaving only Visual Studio 2015 Ultimate CTP5 English.
  
  For example, consider the following scenario:
  • Install Visual Studio 2015 Ultimate Preview Chinese Simplified (FLP) or Visual Studio 2015 Ultimate Preview English plus Visual Studio 2015 Language Pack for Chinese Simplified.
  • Install Visual Studio 2015 Ultimate CTP5 English (FLP).
  In this scenario, you will have Visual Studio 2015 Ultimate with CTP5 level, and all resources are in English.
  
  You cannot install Visual Studio 2015 Ultimate CTP5 first and then install Visual Studio 2015 Ultimate Preview on top. When you try to install an older build on top of a newer build, the installation is blocked.
• The license of Visual Studio is displayed to be expired after you install the product if the location that Visual Studio was saved and installed includes a space in the directory path.
  
  To work around this issue, uninstall Visual Studio and reinstall from a location path that has no spaces.

• Save time debugging complex issues using the new Breakpoint Settings peek window. The window includes improved IntelliSense support for breakpoint conditions and actions.
• Call C++ functions in the Watch and Immediate windows with less worry about deadlocks. If the debugger detects that a called function is deadlocked, it will try to resolve the issue.
• C++ applications start faster when debugging.

• You can now refactor string literals that are littered with escape sequences into a much more easily-readable raw-string format. The supported sequences are \n (new line), \t (tab), \\ (backslash), \' (single quote), \" (double quote), and \? (question mark). To use this feature, right-click any string literal (wide or narrow), and then select Refactor->Convert To Raw String Literal to execute the operation.
• We replaced SmartTags by using LightBulbs for Create Declaration/Definition. This makes it easier for you to see and then click these notifications.
• We integrated the Rename Symbol extension for Visual Studio 2013 (titled Visual C++ Refactoring on Visual Studio Gallery) into Visual Studio and added functionality such as being able to cancel the operation if it takes too long.
• We implemented thread local storage. Use the thread_local keyword to declare that an object should be stored independently for each thread.
• Visual Studio now tries to simplify templates and typedefs in parameter help and quickinfo to make them easier to read.

• Menu Bars will show in Title Case style instead of All Caps style.
• Support for touch in the Visual Studio Editor is now available. This includes touch for scrolling, pinch-to-zoom, tap-and-hold for context menus, double-tap for word selection, and line selection by tapping in the margin.
• The Configuration and Platform dropdown values for the VC Property Page dialog have been changed to remember the last user selection when closed and reopened.
• Users can save custom layouts by clicking Save Window Layout from the Window menu. Users can apply a custom layout by clicking Apply Window Layout from the Window menu, and users can delete, rename, or reorder layouts by clicking Manage Window Layout from the Window menu. The first nine layouts also have keyboard shortcuts from Ctrl+Alt+1 to Ctrl+Alt+9.
• In this CTP, we are rounding out Light Bulbs that are the quick and easy way to obtain helpful fixes for known issues in your code inside the Visual Studio Editor. If you have an issue in your code, placing your editor caret on the line where the issue is shown or resting over the issue will present a light bulb that shows helpful actions that you can take to resolve the problem together with a preview of the results of each action. 
  
  This feature is publicly extensible, so Visual Studio extenders can provide their own suggested actions.
• After you apply this CTP, you can create an empty C# and JavaScript shared project from the File > New Project menu. Phone Projects, Store Projects, and Universal Projects that are written in JavaScript and C# can consume one or many of these shared projects. Shared project references can be managed (added or removed) by using the Reference Manager. Shared Project referencing is also available for some classic desktop C# projects. The project types and languages that support Shared Projects will continue to expand in future CTPs.
• In this CTP, Visual Studio now supports high-resolution icons in the Error List.

Known issues

• Generalized lambda capture: You can assign the result of evaluating an expression to a variable in the capture clause of a lambda. This enables an instance of a move-only type to be captured by value.
• User-defined literals in the language and standard library: You can append numeric and string literals with meaningful suffixes to give them suitable semantics. The compiler transforms these suffixes into calls to appropriate UDL-operator functions. The <chrono>, <string>, and <complex> headers now provide literal operators for convenience. For example, "1729ms" means std::chrono::milliseconds(1729), "meow"s means std::string("meow"), and 3.14i means std::complex<double>(0.0, 3.14).
• Completed noexcept: You can check whether an expression will throw an exception by using the noexcept operator. For example, noexcept(func()) will return "true" if func was specified as noexcept.
• Inline namespaces: You can specify a nested namespace as "inline" to make its contents accessed from its parent namespace.
• Thread-safe "magic" statics: Static local variables are initialized in a thread-safe way, removing the need for manual synchronization. Be aware that usage of these variables other than initialization is still not protected. Thread safety can be disabled by using /Zc:threadSafeInit- to avoid a dependency on the CRT.
• Unrestricted unions: You can define unions that contain types with non-trivial constructors. Constructors for such unions have to be manually defined.
• Finally, all new C++ 11 and C++ 14 language features that are released in the November 2013 compiler CTP for Visual Studio 2013 are also included in this preview. For more information about these features, read this announcement. Briefly, these include the following:
  • __func__, extended sizeof, implicit move generation, ref-qualifiers ("&" and "&&" for member functions), alignof and alignas, and inheriting constructors.
  • auto function return type deduction, decltype(auto), and generic lambdas with a limitation of not using [=]/[&] default capture together with generic lambdas. This will be enabled also for generic lambdas in a future release.
  • Resumable functions and awaitproposed for the C++ Concurrency Technical Specification.
• Null forward iterators: The Standard Library's forward iterators (and stronger) now guarantee that value-initialized iterators compare as equal. This makes it possible to pass an empty range without a parent container. Be aware that generally, value-initialized iterators still cannot be compared to iterators from a parent container.
• quoted(): These manipulators let iostreams preserve strings that contain spaces.
• Heterogeneous associative lookup: When it is Enabled by special comparators (such as the less<> and greater<> transparent operator functors), the ordered associative containers gain templated lookup functions. This lets them work with objects that are comparable to keys, without actually constructing keys.
• integer_sequence: Compile-time integer sequences are now supported to make template metaprogramming easier.
• exchange(): This small utility function makes it convenient to assign a new value to an object and retrieve the old value.
• get<T>(): This lets a tuple element be accessed by its type (when unique) instead of by its index.
• Dual-range equal(), is_permutation(), mismatch(): C++98's "range-and-a-half" algorithms that are taking (first1, last1, first2) are difficult to use correctly. While they are still provided, C++14 has added overloads taking (first1, last1, first2, last2) which are significantly easier and safer to use.
• tuple_element_t: This alias template is added for convenience and consistency with the type traits alias templates.
• Filesystem "V3" Technical Specification (TS): The interface and implementation of <filesystem> are overhauled to follow this TS, which is likely to be incorporated into C++17.
• Library Issues: 24 resolutions have been implemented (for example, is_final, make_reverse_iterator()), not including the resolutions that were already implemented in Visual C++ 2013. Notice that a library issue is a bug report for the Standard. It can be resolved by fixing a specification problem or even adding a small feature.
• <chrono> fixes: The clocks are rewritten to be conformant and precise.
• Minimal allocator fixes: Several library components (including basic_string and std::function) did not work with user-defined allocators implementing C++11's minimal allocator interface, instead requiring C++03's verbose allocator interface. All occurrences of this problem are fixed.
• C99 library features: Most of the remaining C99 library features are implemented.
  • snprintf is implemented.
  • The printf and scanf families of functions now support the new C99 format string improvements.
  • The strtod and scanf families of functions now support hexadecimal floating-point.
  • Library conformance is better improved by software updates and adjustments.
• __restrict: The __restrict keyword is now supported on reference types in addition to pointer types.
• Improved diagnostics: The compiler will now emit warnings about suspicious code that previously would not have resulted in warnings. For example, shadowed variables will now cause warnings. Warnings have also been made clearer.
• The /Wv flag: You can use /Wv:XX.YY.ZZZZ to disable warnings that are introduced after compiler version XX.YY.ZZZZ. Notice that the emitted warnings may still differ from those emitted by the specified version.
• Compiler software updates: We have fixed more than 400 bugs in the compiler. 179 of these were submitted by users through Microsoft Connect.
• Refactored C Runtime (CRT): This CTP contains the first preview of the substantially refactored CRT.
  • msvcr140.dll no longer exists. It is replaced by a trio of DLLs: vcruntime140.dll, appcrt140.dll, and desktopcrt140.dll.
• stdio performance: Many performance improvements are made in the stdio library, notably in the sprintf and sscanf families of functions.
• Object file size reductions: Working together with compiler fixes, the STL's headers are changed to significantly reduce the sizes of object files and static libraries (that is after compilation but before linking. The sizes of linked EXEs/DLLs are unaffected). For example, when you compile a source file that includes all C and C++ Standard Library headers and does nothing else with them, for x86 with /MD /O2, Visual C++ 2013 generated a 731 KB object file. This is improved to be less than 1 KB.
• Debug checking fixes: The STL's debug checks rejected null pointers that are passed as iterators, even when the Standard guaranteed that they should work (for example, merging two [null, null) ranges to a null output). Every algorithm is inspected and fixed.
• Create declaration or definition: You can quickly create a function’s declaration or definition in relation to its neighbors. To do this, right-click the declaration or definition, or use SmartTags.
• Debugger visualizers: Natvis debugger visualization files can be added to a Visual C++ project for easy management and source control integration. Natvis files that are added to a project will take evaluation precedence over visualizers outside the project.
• Native memory diagnostics:
  • You can start a memory diagnostic session (Alt+F2) that monitors the live memory usage of your native application. This supports Windows Desktop.
  • You can capture heap snapshots of the running process in memory to see the types and instances for native allocations.
  • You can view the difference in memory allocations between two memory snapshots.
  • You can dive into the memory contents of a process snapshot by using the debugger for deeper analysis of the heap.

Known issues