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What's the need of array with zero elements?

... This is a way to have variable sizes of data, without having to call malloc (kmalloc in this case) twice. You would use it like this: struct bts_action *var = kmalloc(sizeof(*var) + extra, GFP_KERNEL); This used to be not standard and was considered a hack (as Aniket said), but it was s...
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Types in MySQL: BigInt(20) vs Int(20)

...gInt , MediumInt , and Int are... it would seem obvious that they would allow for larger numbers; however, I can make an Int(20) or a BigInt(20) and that would make seem that it is not necessarily about size. ...
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Rails raw SQL example

... and then you'd need to call values on this PG::Result object to get the results array – jobwat Mar 26 '14 at 1:00 3 ...
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What is a good pattern for using a Global Mutex in C#?

...id ); // Need a place to store a return value in Mutex() constructor call bool createdNew; // edited by Jeremy Wiebe to add example of setting up security for multi-user usage // edited by 'Marc' to work also on localized systems (don't use just "Everyone") var allowEveryoneRu...
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How can I replace every occurrence of a String in a file with PowerShell?

Using PowerShell, I want to replace all exact occurrences of [MYID] in a given file with MyValue . What is the easiest way to do so? ...
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Use underscore inside Angular controllers

...derscore, it attaches itself to the window object, and so is available globally. So you can use it from Angular code as-is. You can also wrap it up in a service or a factory, if you'd like it to be injected: var underscore = angular.module('underscore', []); underscore.factory('_', ['$window', fu...
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MySQL, Check if a column exists in a table with SQL

...pecific column, and if not — create it. Otherwise do nothing. This is really an easy procedure in any enterprise-class database, yet MySQL seems to be an exception. ...
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How to count the number of set bits in a 32-bit integer?

...Hamming Weight', 'popcount' or 'sideways addition'. The 'best' algorithm really depends on which CPU you are on and what your usage pattern is. Some CPUs have a single built-in instruction to do it and others have parallel instructions which act on bit vectors. The parallel instructions (like x86's ...
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How to increase the vertical split window size in Vim

:vsplit (short form: :vs ) split the Vim viewport vertically. :30vs splits the viewport, making the new window 30 characters wide. Once this 30 char window is created, how would one change it's size to 31 or 29? ...
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Replacing a 32-bit loop counter with 64-bit introduces crazy performance deviations with _mm_popcnt_

...AMD documents it and compilers don't expose it.) (Yes, these instructions all run on the same execution unit). This dependency doesn't just hold up the 4 popcnts from a single loop iteration. It can carry across loop iterations making it impossible for the processor to parallelize different loop...