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Why do std::shared_ptr work
...g delete). When the shared_ptr is destroyed, it calls that stored function and that will call the deleter.
A simple sketch of the type erasure that is going on simplified with std::function, and avoiding all reference counting and other issues can be seen here:
template <typename T>
void del...
How to parse a string into a nullable int
...eturn null;
}
Edit @Glenn int.TryParse is "built into the framework". It and int.Parse are the way to parse strings to ints.
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Can virtual functions have default parameters?
If I declare a base class (or interface class) and specify a default value for one or more of its parameters, do the derived classes have to specify the same defaults and if not, which defaults will manifest in the derived classes?
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Why is address zero used for the null pointer?
...ll pointer in C source while represented differently at runtime. The C++ standard has a note that makes clear that converting "an integral constant expression with value zero always yields a null pointer, but converting other expressions that happen to have value zero need not yield a null pointer"....
Why does 'git commit' not save my changes?
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As the message says:
no changes added to commit (use "git add" and/or "git commit -a")
Git has a "staging area" where files need to be added before being committed, you can read an explanation of it here.
For your specific example, you can use:
git commit -am "save arezzo files"
(...
Freeze the top row for an html table only (Fixed Table Header Scrolling) [duplicate]
...pany to research a solution for this that could function in IE7+, Firefox, and Chrome.
After many moons of searching, trying, and frustration it really boiled down to a fundamental problem. For the most part, in order to gain the fixed header, you need to implement fixed height/width columns becaus...
Comments in command-line Zsh
I switched quite recently from Bash to Zsh on Ubuntu and I'm quite happy about it. However, there is something I really miss and I did not find how to achieve the same thing.
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How to do associative array/hashing in JavaScript
...h new Array() is frowned up. The article eventually mentions its drawbacks and suggests new Object() or {} as preferred alternatives, but that's near the end and I fear most readers won't get that far.
– Daniel Lubarov
May 16 '15 at 5:55
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Authenticate Jenkins CI for Github private repository
...h that task.. Tried the documentation, generating ssh-key for jenkins user and all what I can see is: "unable to clone the repo". I've checked URLs - they are valid.
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Create PostgreSQL ROLE (user) if it doesn't exist
...sword';
END IF;
END
$do$;
(Building on @a_horse_with_no_name's answer and improved with @Gregory's comment.)
Unlike, for instance, with CREATE TABLE there is no IF NOT EXISTS clause for CREATE ROLE (up to at least pg 12). And you cannot execute dynamic DDL statements in plain SQL.
Your reques...