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How to test if parameters exist in rails
...re asking about existence. You might need to differentiate:
Not there at all.
There but nil.
There but false.
There but an empty string.
as well. Hard to say without more details of your precise situation.
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How do you follow an HTTP Redirect in Node.js?
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It is. It's called http.request the API is pretty simple.
– Raynos
Oct 23 '12 at 20:24
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Is std::vector so much slower than plain arrays?
...d the array only once. Note: when you resize() the vector you are not only allocating the memory but also running through the vector and calling the constructor on each member.
Re-Arranging the code slightly so that the vector only initializes each object once:
std::vector<Pixel> pixels(di...
How do I suspend painting for a control and its children?
... and reflector usage I came across the WM_SETREDRAW win32 message. This really stops controls drawing whilst you update them and can be applied, IIRC to the parent/containing panel.
This is a very very simple class demonstrating how to use this message:
class DrawingControl
{
[DllImport("user...
Why doesn't await on Task.WhenAll throw an AggregateException?
... been some changes to exception handling, but the newest docs for Task.WhenAll state "If any of the supplied tasks completes in a faulted state, the returned task will also complete in a Faulted state, where its exceptions will contain the aggregation of the set of unwrapped exceptions from each of ...
How do I check if a type provides a parameterless constructor?
...Type.EmptyTypes, null);
There's a caveat for value types, which aren't allowed to have a default constructor. You can check if you have a value type using the Type.IsValueType property, and create instances using Activator.CreateInstance(Type);
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How to get the Android device's primary e-mail address
...ntManager.getAccounts or AccountManager.getAccountsByType to get a list of all account names on the device. Fortunately, for certain account types (including com.google), the account names are email addresses. Example snippet below.
Pattern emailPattern = Patterns.EMAIL_ADDRESS; // API level 8+
Acc...
Why should I learn Lisp? [closed]
I really feel that I should learn Lisp and there are plenty of good resources out there to help me do it.
29 Answers
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Change first commit of project with Git? [duplicate]
...want to change something in the first commit of my project with out losing all subsequent commits. Is there any way to do this?
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How do I update a Python package?
I'm running Ubuntu 9:10 and a package called M2Crypto is installed (version is 0.19.1). I need to download, build and install the latest version of the M2Crypto package (0.20.2).
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