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How do I create a unique constraint that also allows nulls?
...able won't let me store NULLs in a unique column in the first place. If anyone knows a solution for that, please post it here
– dotNET
Feb 2 '15 at 22:01
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setNeedsLayout vs. setNeedsUpdateConstraints and layoutIfNeeded vs updateConstraintsIfNeeded
...out autolayouts–says:
If something changes later on that invalidates one of your constraints, you should remove the constraint immediately and call setNeedsUpdateConstraints. In fact, that’s the only case where you should have to trigger a constraint update pass.
In addition, in my experie...
Why would an Enum implement an Interface?
... - e.g. you may have interfaces such as Printable, Reportable etc. and components that support these.
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sed command with -i option failing on Mac, but works on Linux
...the manual which explains nothing about it. Then you google it to find someone else also has the same problem. I mean, why not giving example in the manual?
– lukmac
Aug 19 '12 at 22:43
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How to convert std::string to LPCSTR?
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The MultiByteToWideChar answer that Charles Bailey gave is the correct one. Because LPCWSTR is just a typedef for const WCHAR*, widestr in the example code there can be used wherever a LPWSTR is expected or where a LPCWSTR is expected.
One minor tweak would be to use std::vector<WCHAR> in...
orderBy multiple fields in Angular
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Sorting can be done by using 'orderBy' filter in angular.
Two ways:
1. From view
2. From controller
From view
Syntax:
{{array | orderBy : expression : reverse}}
For example:
<div ng-repeat="user in users | orderBy : ['nam...
Why does GCC generate 15-20% faster code if I optimize for size instead of speed?
...ot show this weird behavior.
Of course, if an inappropriate alignment is done, it makes things worse. An unnecessary / bad alignment just eats up bytes for no reason and potentially increases cache misses, etc.
The noise it makes pretty much makes timing micro-optimizations
impossible.
H...
dynamic_cast and static_cast in C++
...ptr and tries to safely cast it to a pointer of type Type*. This cast is done at compile time. It will only perform the cast if the type types are related. If the types are not related, you will get a compiler error. For example:
class B {};
class D : public B {};
class X {};
int main()
{
D*...
Get list of passed arguments in Windows batch script (.bat)
...re command line starting from n-th parameter.
– Van Jone
Mar 14 '13 at 11:45
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Are JavaScript strings immutable? Do I need a “string builder” in JavaScript?
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In the same way, if you have two references to the same string, modifying one doesn't affect the other
let a = b = "hello";
a = a + " world";
// b is not affected
However, I've always heard what Ash mentioned in his answer (that using Array.join is faster for concatenation) so I wanted to test o...