Interfacing with Objective-C<\/h3>\n
DMD has had limited support for binding with Objective-C for some time. This release expands that support to include classes, instance variables, and super calls.<\/p>\n
Previously, binding with Objective-C classes required using D interfaces. No longer. Now, Objective-C classes can be declared directly as D classes<\/a>. Decorate an Objective-C class with To better facilitate interaction between the two languages, such classes have slightly modified behavior. Any It\u2019s also now possible to declare instance variables<\/a> in Objective-C classes and for a method in an Objective-C class to make a super call<\/a>.<\/p>\n Perhaps the biggest of the GC news items is that DRuntime now ships with a precise garbage collector<\/a>. This can be enabled on any executable compiled and linked against the latest DRuntime by passing the runtime option Another new GC configuration option controls the behavior of the GC at program termination<\/a>. Currently, the GC runs a collection at termination. This is to present the opportunity to finalize any live objects still holding on to resources that might affect the system state. However, this doesn\u2019t guarantee all objects will be finalized as roots may still exist, nor is the need for it very common, so it\u2019s often just a waste of time. As such, a new This can be passed on the command line of a program compiled and linked against DRuntime as, e.g. All DRuntime options, including the two new ones, can be set up in code rather than being passed on the command line by declaring and initializing an array of strings called See the documentation on configuring the garbage collector<\/a> for more GC options.<\/p>\n Additional GC-related enhancements include programmatic access to GC profiling statistics<\/a> and a new GC registry<\/a> that allows user-supplied GCs to be linked with the runtime (see the documentation for details<\/a>).<\/p>\n There are two enhancements to D\u2019s C++ interface in this release. The first is found in the new DRuntime module, There are two interesting perks for conference goers this year.<\/p>\n We now have an \u201cofficial\u201d gathering spot. Usually at DConf, we pick an \u201cofficial\u201d hotel where the D Language Foundation folks and many attendees stay, but where a number of conference goers gather in the evenings after dinner. This year, a number of factors made it difficult to pick a reasonable spot, so we opted for something different.<\/p>\n There\u2019s a cozy little pub around the corner from the venue, the Prince Arthur, that has a nice room on the second floor available for reservation. There\u2019s a limit on how many bodies we can pack in there at once, but folks generally come and go throughout the evening anyway. Any overflow can head downstairs to the public area. We\u2019ve got the room May 8, 9, and 10.<\/p>\n Additionally, we\u2019ll be offering a couple of free rounds each night courtesy of Mercedes-Benz Research & Development North America. Free drinks in a cozy backstreet London pub sounds like a great way to pass the time!<\/p>\n Check out the DConf venue page<\/a> for details about the Prince Arthur and how to get there.<\/p>\n Julian McDonnell of Joolz Guides<\/a> will be taking some DConf registrants on a guided walk May 6 and 7. If you\u2019ve never seen his YouTube channel<\/a>, we recommend it. His video guides are quirky, informative, and fun.<\/p>\n This is available for free to all registrants, but space is limited<\/strong>! When you register for DConf<\/a>, you\u2019ll receive information on how to reserve your spot. We\u2019ve arranged to have the tours in the mid-afternoon on both days so that folks arriving in the morning will have a chance to participate. This is a walking tour that will last somewhere between 3 – 4 hours, so be sure to wear comfortable shoes.<\/p>\n The current plan is to start at Temple Station and end at London Bridge. We hope you join us!<\/p>\nextern(Objective-C)<\/code>, make use of the @selector<\/code> attribute on the methods, and away you go.<\/p>\nstatic<\/code> and final<\/code> methods in an extern(Objective-C)<\/code> class are virtual. However, final<\/code> methods still are forbidden from being overridden by subclasses. static<\/code> methods are overridable.<\/p>\nextern (Objective-C)\r\nclass NSObject\r\n{\r\n static NSObject alloc() @selector(\"alloc\");\r\n NSObject init() @selector(\"init\");\r\n void release() @selector(\"release\");\r\n}\r\n\r\nextern (Objective-C)\r\nclass Foo : NSObject\r\n{\r\n override static Foo alloc() @selector(\"alloc\");\r\n override Foo init() @selector(\"init\");\r\n\r\n int bar(int a) @selector(\"bar:\")\r\n {\r\n return a;\r\n }\r\n}\r\n\r\nvoid main()\r\n{\r\n auto foo = Foo.alloc.init;\r\n scope (exit) foo.release();\r\n\r\n assert(foo.bar(3) == 3);\r\n}<\/pre>\nextern (Objective-C)\r\nclass NSObject\r\n{\r\n void release() @selector(\"release\");\r\n}\r\n\r\nextern (Objective-C)\r\nclass Foo : NSObject\r\n{\r\n \/\/ instance variable\r\n int bar;\r\n\r\n int foo() @selector(\"foo\")\r\n {\r\n return 3;\r\n }\r\n\r\n int getBar() @selector(\"getBar\")\r\n {\r\n return bar;\r\n }\r\n}\r\n\r\nextern (Objective-C)\r\nclass Bar : Foo\r\n{\r\n static Bar alloc() @selector(\"alloc\");\r\n Bar init() @selector(\"init\");\r\n\r\n override int foo() @selector(\"foo\")\r\n {\r\n \/\/ super call\r\n return super.foo() + 1;\r\n }\r\n}<\/pre>\nNew GC stuff<\/h3>\n
--DRT-gcopt=gc:precise<\/code>. To be clear, this is not<\/em> a DMD compiler option. Read the documentation on the precise GC<\/a> for more info.<\/p>\ncleanup<\/code> option allows the user of a D program to specify three possible approaches to GC clean up at program termination:<\/p>\n\n
collect<\/code>: the default, current, behavior for backward compatibility<\/li>\nnone<\/code>: do no cleanup at all<\/li>\nfinalize<\/code>: unconditionally finalize all live objects<\/li>\n<\/ul>\n--DRT-gcopt=cleanup:finalize<\/code>.<\/p>\nrt_options<\/code>. It must be both extern(C)<\/code> and __gshared<\/code>:<\/p>\nextern(C) __gshared string[] rt_options = [\"gcopt=gc:precise cleanup:none\"];<\/pre>\n
Standard C++<\/h3>\n
core.stdcpp.new_<\/code><\/a>. This provides access to the global C++ new<\/code> and delete<\/code> operators so that D programs can allocate from the C++ heap. The second is the new core.stdcpp.allocator<\/code> module<\/a>, which exposes the std::allocator<T><\/code> class of C++ as a foundation for binding to the STL container types that allocate.<\/p>\nDConf 2019 news<\/h2>\n
![\"\"](\"http:\/\/dlang.org\/blog\/wp-content\/uploads\/2019\/01\/dconf_logo_2019.jpg\"){kind=logo}
<\/p>\nThe nightly gathering spot<\/h3>\n
A free tour by Joolz Guides<\/h3>\n