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How to determine if a record is just created or updated in after_save
The #new_record? function determines if a record has been saved. But it is always false in the after_save hook. Is there a way to determine whether the record is a newly created record or an old one from update?
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What's is the difference between train, validation and test set, in neural networks?
I'm using this library to implement a learning agent.
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How can I capitalize the first letter of each word in a string?
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18 Answers
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Difference between Role and GrantedAuthority in Spring Security
There are concepts and implementations in Spring Security, such as the GrantedAuthority interface to get an authority to authorize/control an access.
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Use 'class' or 'typename' for template parameters? [duplicate]
When defining a function template or class template in C++, one can write this:
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Defining a variable with or without export
What is export for?
14 Answers
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How to debug heap corruption errors?
I am debugging a (native) multi-threaded C++ application under Visual Studio 2008. On seemingly random occasions, I get a "Windows has triggered a break point..." error with a note that this might be due to a corruption in the heap. These errors won't always crash the application right away, altho...
Why is no one using make for Java?
Just about every Java project that I've seen either uses Maven or Ant. They are fine tools and I think just about any project can use them. But what ever happened to make ? It's used for a variety of non-Java projects and can easily handle Java. Sure you have to download make.exe if you use Win...
In Markdown, what is the best way to link to a fragment of a page, i.e. #some_id?
I'm trying to figure out how to reference another area of a page with Markdown. I can get it working if I add a
5 Answers
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Is there a performance difference between i++ and ++i in C?
Is there a performance difference between i++ and ++i if the resulting value is not used?
14 Answers
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