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Shall we always use [unowned self] inside closure in Swift
... in order to make sure that it is still around by the time the closure is called.
Example: Making an asynchronous network request
If you are making an asynchronous network request you do want the closure to retain self for when the request finishes. That object may have otherwise been deallocated ...
How to version control a record in a database
...O table. Happy days.
Then, I would create a FOO_HISTORY table. This has all the columns of the FOO table. The primary key is the same as FOO plus a RevisionNumber column. There is a foreign key from FOO_HISTORY to FOO. You might also add columns related to the revision such as the UserId and R...
Should I store entire objects, or pointers to objects in containers?
... storing pointers into vector can be efficient if used along with a custom allocator for the pointees. The custom allocator has to take care of the cache locality, for example using placement new (see en.wikipedia.org/wiki/Placement_syntax#Custom_allocators).
– amit
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How to grep a text file which contains some binary data?
... Yes, except that this won't work on OSX unless you do the following: LC_ALL="C" grep -a
– Chris Stratton
Feb 10 '19 at 18:05
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Does Java SE 8 have Pairs or Tuples?
..., value[i]) , then filter based on the second value[i] element, and finally output just the indices.
9 Answers
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Remove padding from columns in Bootstrap 3
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You'd normally use .row to wrap two columns, not .col-md-12 - that's a column encasing another column. Afterall, .row doesn't have the extra margins and padding that a col-md-12 would bring and also discounts the space that a column wo...
How do I list the functions defined in my shell?
I can type alias to show a list of all the aliases.
8 Answers
8
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Combining multiple commits before pushing in Git [duplicate]
I have a bunch of commits on my local repository which are thematically similar. I'd like to combine them into a single commit before pushing up to a remote. How do I do it? I think rebase does this, but I can't make sense of the docs.
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PHP 5.4 Call-time pass-by-reference - Easy fix available?
Is there any way to easily fix this issue or do I really need to rewrite all the legacy code?
3 Answers
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Order data frame rows according to vector with specific order
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I prefer to use ***_join in dplyr whenever I need to match data. One possible try for this
left_join(data.frame(name=target),df,by="name")
Note that the input for ***_join require tbls or data.frame
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