Performance The bottom line is this: if type checking is done at compile time rather than at run time, performance improves. The CLR simply works out the details-no more code bloat! As an added value, generics code is generated at run time, so two expansions over unrelated element types such as GenericSortedList and GenericSortedList are able to reuse most of the same just-in-time (JIT)-compiled code. With GenericSortedList, all you need to do is instantiate the type with the desired element type as T. The problem with this approach is that new code has to be written for every type for which you want a type-safe list, which can quickly become laborious. This allows for specifying and checking the type of the elements at compile time rather than at run time.īinary code reuse For maintenance purposes, a developer may elect to achieve compile-time type safety using SortedList by deriving a SortedListOfStrings from it. In contrast, a use of GenericSortedList where T is typed to String causes all add and lookup methods to work with String references. This lack of type safety at compile time is both tedious for the developer and prone to error. Similarly, if a String object is retrieved from the list, it must be cast at run time from an Object reference to a String reference. Type safety When a user adds a String to a collection of type SortedList, there is an implicit cast to Object. As an example let's take two hypothetical collection classes: SortedList, a collection of Object references, and GenericSortedList, a collection of any type. I'll briefly describe these benefits, and as you read the rest of this column, you'll understand them in more detail. Some of the strengths of CLR generics are compile-time type safety, binary code reuse, performance, and clarity. However, I hesitate to draw too much of a comparison between CLR generics and C++ templates because generics have some additional benefits, including the absence of two common problems: code bloat and developer confusion. Those of you who are familiar with templates in C++ will find that generics serve a similar purpose in managed code. Finally, the research group at Microsoft has modified a version of the shared source common language implementation (CLI), code-named "Rotor," to include generics support.Īs with any new technology, it is helpful to ask just why it's useful. Meanwhile, in the same release of the CLR, there is a planned update to the language and compiler that takes full advantage of generics. Just how far in the future are generics? Microsoft plans to ship generics in the release of the CLR code-named "Whidbey," and there should be a beta release of the Whidbey CLR sometime after this column goes to press. The name generics reflects the goal of the feature: to enable the writing of code while not specifying details that might limit the scope of its usefulness. The code that references the generic type fills in the missing details, tailoring the type to its particular needs. Instead, these details are specified when the code is referenced by consumer code. Generics are an extension to the CLR's type system that allow developers to define types for which certain details are left unspecified. I'll introduce generics and discuss the benefits that it brings to your code, and in a future column I'll dig into more details of how the compiler and runtime implement generics. In contrast, this month I'm going to peek into the future by looking at a cool new feature, generics, which will be coming soon to the common language runtime (CLR). In some ways this topic revisited the past by showing how your managed code can access legacy Win32® code. Try a complementary or analogous colored background to make your logo stand out.In the last installment of this column, I covered Interop with unmanaged code via P/Invoke. If you want to pair your site’s logo with a matching background image, color palettes will help create comforting contrasts.Choose a minimalistic but interesting image that leaves room for the important stuff, like a headline or button. If you plan to layer your background image with design elements or text, pick an image that’s not too intrusive or bold.Do you want a serious or laid-back mood? Do you have creative branding, or is your identity more traditional? Are there colors you need to follow from your brand guidelines? These are considerations that will guide your choice of backgrounds. When choosing a background image for your website, keep the user experience you’d like to communicate in mind.You may need a background image as a header on your homepage or for the entire page layout. A website, unlike a social media page, tells your visitors everything about you, your brand, or your project. Websites are probably the most popular use case for background images.
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