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How does free know how much to free?
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FYI, for example BSD has malloc_size() to reliably access the block size from an malloc()ed pointer. But there's no reliable, portable way.
– laalto
Oct 5 '09 at 7:53
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Way to ng-repeat defined number of times instead of repeating over array?
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Update (9/25/2018)
Newer versions of AngularJS (>= 1.3.0) allow you to do this with only a variable (no function needed):
<li ng-repeat="x in [].constructor(number) track by $index">
<span>{{ $index+1 }}</span>
</li>
$scope.number = 5;
This was not poss...
How to check if a value exists in a dictionary (python)
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it wasn't necesarry after all, unless run on bigger dict. I guess overhead in values() is caused by copying the value list and in viewvalues() by maintaining the view alive.
– soulcheck
Nov 21 '11 at 17:12
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How to delete migration files in Rails 3
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I usually:
Perform a rake db:migrate VERSION=XXX on all environments, to the version before the one I want to delete.
Delete the migration file manually.
If there are pending migrations (i.e., the migration I removed was not the...
Why do we need message brokers like RabbitMQ over a database like PostgreSQL?
...ustering options are also available.
In regards to AMQP, I would say a really cool feature is the "exchange", and the ability for it to route to other exchanges. This gives you more flexibility and enables you to create a wide array of elaborate routing typologies which can come in very handy when...
Send and receive messages through NSNotificationCenter in Objective-C?
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@implementation TestClass
- (void) dealloc
{
// If you don't remove yourself as an observer, the Notification Center
// will continue to try and send notification objects to the deallocated
// object.
[[NSNotificationCenter defaultCenter] removeO...
Debug vs Release in CMake
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With CMake, it's generally recommended to do an "out of source" build. Create your CMakeLists.txt in the root of your project. Then from the root of your project:
mkdir Release
cd Release
cmake -DCMAKE_BUILD_TYPE=Release ..
make
And for Debug (...
How to get a Docker container's IP address from the host
...n. Maybe provide two examples clearly labelled Linux and Windows. I literally just typed the example, checked the docs which also uses single quotes and then Googled the error. I'm sure I'm not alone.
– Wyck
Apr 15 '19 at 18:42
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find() with nil when there are no records
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Yes, just do:
Challenge.find_by_id(10)
For Rails 4 and 5:
Challenge.find_by(id: 10)
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Append TimeStamp to a File Name
... to a file using the Path class and string manipulation is not an issue at all. this only an alternative to DateTime.ToString Method (String) or string.Format("{0:yyyy-MM-dd_hh-mm-ss-tt}",DateTime.Now);
– Joseph
Jun 26 '17 at 11:50
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