大约有 7,700 项符合查询结果(耗时:0.0210秒) [XML]

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How to return smart pointers (shared_ptr), by reference or by value?

...void needless copies: get_names(std::vector<std::string>& out_param ); ... std::vector<std::string> names; get_names( names ); Unfortunately, this approach is far from ideal. The code grew by 150% We’ve had to drop const-ness because we’re mutating names. As ...
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How to display unique records from a has_many through relationship?

...uite useful. Here's the code OrdersController#show @order = Order.find(params[:id]) @order_items_by_photo = @order.order_items.group_by(&:photo) @order_items_by_photo then looks something like this: => {#<Photo id: 128>=>[#<OrderItem id: 2, photo_id: 128>, #<OrderIt...
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When do you use map vs flatMap in RxJava?

...vable and emits it. Say for example we've a method titleCase(String inputParam) that returns Titled Cased String object of the input param. The return type of this method can be String or Observable<String>. If the return type of titleCase(..) were to be mere String, then you'd use map(s -...
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How To Format A Block of Code Within a Presentation? [closed]

I am preparing a presentation using Google Slides, though I can also work on the presentation within Open Office that will include code snippets. ...
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Automapper - how to map to constructor parameters instead of property setters

...s a treat for me; AutoMapper currently doesn't like constructors where all parameters are optional, so I just use .ConstructUsing(x => new MyClass()); – David Keaveny Apr 11 '11 at 23:56 ...
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Writing handler for UIAlertAction

... Instead of self in your handler, put (alert: UIAlertAction!). This should make your code look like this alert.addAction(UIAlertAction(title: "Okay", style: UIAlertActionStyle.Default, handler: {(alert: UIAlertAction!) in pri...
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Asynctask vs Thread in android

...Invoked on the UI thread before the task is executed doInbackground(Params..) Invoked on the background thread immediately after onPreExecute() finishes executing. onProgressUpdate(Progress..) Invoked on the UI thread after a call to publishProgress(Progress...). onPos...
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Could not locate Gemfile

I'm certainly no Ruby developer but I have an application on my server using Ruby, Gems, and Bundler. I am trying to install another Ruby on under a different user account but on the same VPS. When I go to run ...
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Are there benefits of passing by pointer over passing by reference in C++?

... A pointer can receive a NULL parameter, a reference parameter can not. If there's ever a chance that you could want to pass "no object", then use a pointer instead of a reference. Also, passing by pointer allows you to explicitly see at the call site w...
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What's the difference between std::move and std::forward

...sing it. std::forward has a single use case: to cast a templated function parameter (inside the function) to the value category (lvalue or rvalue) the caller used to pass it. This allows rvalue arguments to be passed on as rvalues, and lvalues to be passed on as lvalues, a scheme called "perfect fo...