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When and how should I use a ThreadLocal variable?
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One possible (and common) use is when you have some object that is not thread-safe, but you want to avoid synchronizing access to that object (I'm looking at you, SimpleDateFormat). Instead, give each thread its own instance of the object...
Non-static variable cannot be referenced from a static context
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You must understand the difference between a class and an instance of that class. If you see a car on the street, you know immediately that it's a car even if you can't see which model or type. This is because you compare what you see with t...
Debug.Assert vs Exception Throwing
I've read plenty of articles (and a couple of other similar questions that were posted on StackOverflow) about how and when to use assertions, and I understood them well. But still, I don't understand what kind of motivation should drive me to use Debug.Assert instead of throwing a plain excep...
How to remove unused C/C++ symbols with GCC and ld?
I need to optimize the size of my executable severely ( ARM development) and
I noticed that in my current build scheme ( gcc + ld ) unused symbols are not getting stripped.
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What is the difference between Forking and Cloning on GitHub?
I'd like to know the differences between doing a Fork of a project and doing a clone of it.
9 Answers
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Schrödingers MySQL table: exists, yet it does not
...er_table, check the data directory to make sure you have both an .frm file and .ibd file for the table in question. If it's MYISAM, there should be a .frm, .MYI and a .MYD file.
The problem can usually be resolved by deleting the orphaned file manually.
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NULL values inside NOT IN clause
...t I thought were identical queries one using a not in where constraint and the other a left join . The table in the not in constraint had one null value (bad data) which caused that query to return a count of 0 records. I sort of understand why but I could use some help fully grasping the con...
What is the difference between an int and a long in C++?
... (an answer by example) with some of the details below regarding the C++ standard. The draft for C++0x is at open-std.org/JTC1/SC22/WG21/docs/papers/2008/n2798.pdf and it is marked up so you can see the differences between it and the last rev.
– Patrick Johnmeyer
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Java: getMinutes and getHours
How do you get Hours and Minutes since Date.getHours and Date.getMinutes got deprecated? The examples that I found on Google search used the deprecated methods.
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How to move screen without moving cursor in Vim?
I recently discovered Ctrl + E and Ctrl + Y shortcuts for Vim that respectively move the screen up and down with a one line step, without moving the cursor .
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