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Fully custom validation error message with Rails
...ssages can be set for a specific model+attribute, model, attribute, or globally.
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Eclipse executable launcher error: Unable to locate companion shared library
I had Eclipse Indigo installed on my computer with the Android plugin and it was working perfectly for about two weeks. Today, I updated java and quicktime then restarted my computer. When it booted back up, eclipse had completely vanished - all the program files have completely disappeared. When I ...
HashSet versus Dictionary w.r.t searching time to find if an item exists
...s for Dictionary is so fast that there is no benefit from using HashSet at all, in the OP's case.
– EtherDragon
Jul 27 '12 at 23:03
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Make a borderless form movable?
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This article on CodeProject details a technique. Is basically boils down to:
public const int WM_NCLBUTTONDOWN = 0xA1;
public const int HT_CAPTION = 0x2;
[System.Runtime.InteropServices.DllImport("user32.dll")]
public static extern int SendMessage(IntPtr hWnd, int Msg, int wParam...
How to Sort a List by a property in the object
I have a class called Order which has properties such as OrderId , OrderDate , Quantity , and Total . I have a list of this Order class:
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Is there a portable way to print a message from the C preprocessor?
...ng is not going to be great, as warnings are treated as errors for us generally, and we'd really like the message to be informational, rather than stop the compilation.
– Danny S
Mar 23 '15 at 4:10
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Dealing with multiple Python versions and PIP?
...ple versions of Python? For example, I want to use pip to explicitly install things to either my site 2.5 installation or my site 2.6 installation.
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NumPy array initialization (fill with identical values)
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On my system (Python 2.7, Numpy 1.8), np.full() is actually slightly slower than np.empty() followed by np.fill().
– John Zwinck
Jul 25 '14 at 8:37
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What is the 'instanceof' operator used for in Java?
... Dog is Dog
dog instanceof Object // true - Object is the parent type of all objects
However, with Object animal = new Animal();,
animal instanceof Dog // false
because Animal is a supertype of Dog and possibly less "refined".
And,
dog instanceof Cat // does not even compile!
This is beca...
Why do we need a pure virtual destructor in C++?
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Probably the real reason that pure virtual destructors are allowed is that to prohibit them would mean adding another rule to the language and there's no need for this rule since no ill-effects can come from allowing a pure virtual destructor.
Nope, plain old virtual is enough.
If...