How is this form of scoping called?

More or less by accident I stumbled upon this form of scoping ``` DataSource *dataSource =({ NSInteger idx = [[self.tableView indexPathForSelectedRow] row]; DataSource *dataSource = [DataSource new]; dataSource.address = self.destinations[idx][0]; dataSource.name = self.destinations[idx][1]; dataSource; }); ``` I think it is a nice way to create and instantiate objects and variables as temporary variables will only live as long as they are needed to create the object I really need and care for. In the code above `idx` will be gone as soon as I write the inner `dataSource` to the outer `dataSource`, as the scope will be left soon after. Also I find the fact appealing that a fully instantiated and configured object will be set to the outer object. Actually I don't even know if this is a C or Objective-C feature or a syntax candy added to clang. @Unheilig this is a syntax for organizing code. it is not something like a block or closure. at the end of the code you just have a fully instantiated and configured object. This comes in handy if you need an object only to pass it as an argument to a method, but the configuration of that object takes more than one statement. Instead of assigning it to a local temporary variable you can pass in a statement expression. ``` [[MYViewController alloc] initWithDataSource:({ NSInteger idx = [[self.tableView indexPathForSelectedRow] row]; DataSource *dataSource = [DataSource new]; dataSource.address = self.destinations[idx][@"address"]; dataSource.name = self.destinations[idx][@"name"]; dataSource; })]; ``` In a non-ARC environment you could even call autorelease inside the expression statement. So it is just about code organization and a lot of personal taste I guess.