大约有 42,000 项符合查询结果(耗时:0.0439秒) [XML]

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How can I add reflection to a C++ application?

I'd like to be able to introspect a C++ class for its name, contents (i.e. members and their types) etc. I'm talking native C++ here, not managed C++, which has reflection. I realise C++ supplies some limited information using RTTI. Which additional libraries (or other techniques) could supply this ...
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How do I sort a dictionary by value?

I have a dictionary of values read from two fields in a database: a string field and a numeric field. The string field is unique, so that is the key of the dictionary. ...
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Why do we need break after case statements?

Why doesn't the compiler automatically put break statements after each code block in the switch? Is it for historical reasons? When would you want multiple code blocks to execute? ...
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A numeric string as array key in PHP

Is it possible to use a numeric string like "123" as a key in a PHP array, without it being converted to an integer? 11 A...
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Dynamically select data frame columns using $ and a character value

I have a vector of different column names and I want to be able to loop over each of them to extract that column from a data.frame. For example, consider the data set mtcars and some variable names stored in a character vector cols . When I try to select a variable from mtcars using a dynamic s...
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What is the purpose of wrapping whole Javascript files in anonymous functions like “(function(){ … }

I have been reading a lot of Javascript lately and I have been noticing that the whole file is wrapped like the following in the .js files to be imported. ...
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What are good alternatives to SQL (the language)? [closed]

I occasionally hear things about how SQL sucks and it's not a good language, but I never really hear much about alternatives to it. So, are other good languages that serve the same purpose (database access) and what makes them better than SQL? Are there any good databases that use this alternative l...
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Create instance of generic type whose constructor requires a parameter?

If BaseFruit has a constructor that accepts an int weight , can I instantiate a piece of fruit in a generic method like this? ...
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Why do people use Heroku when AWS is present? What distinguishes Heroku from AWS? [closed]

I'm a beginner RoR programmer who's planning to deploy my app using Heroku. Word from my other advisor friends says that Heroku is really easy, good to use. The only problem is that I still have no idea what Heroku does... ...
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Best architectural approaches for building iOS networking applications (REST clients)

I'm an iOS developer with some experience and this question is really interesting to me. I saw a lot of different resources and materials on this topic, but nevertheless I'm still confused. What is the best architecture for an iOS networked application? I mean basic abstract framework, patterns, whi...