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How to do an instanceof check with Scala(Test)
I'm trying to incorporate ScalaTest into my Java project; replacing all JUnit tests with ScalaTests. At one point, I want to check if Guice's Injector injects the correct type. In Java, I have a test like this:
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How can I convert a datetime object to milliseconds since epoch (unix time) in Python?
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Worth mentioning that if all you want is a true unix timestamp as defined here en.wikipedia.org/wiki/Unix_time (and so will only be using the unix_time function from this answer) then you should wrap delta.total_seconds() with int to avoid ending up ...
What is the difference between an int and a long in C++?
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Some compilers even have flags that allow you to modify the default size of int and long ie force them to 8 or 16 etc. See you compiler documentation for details.
– Martin York
Nov 7 '08 at 17:27
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Daylight saving time and time zone best practices [closed]
...hanged from the original value recorded.
When scheduling future events, usually local time is preferred instead of UTC, as it is common for the offset to change. See answer, and blog post.
When storing whole dates, such as birthdays and anniversaries, do not convert to UTC or any other time zone.
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How to set a timer in android
...pplication has acquired a wakeLock and hence you are sure that the phone shall not go into the sleep state. If phone does go to the sleep state then sendMessageDelayed as well as sendMessageAtTime will not work. Hence in that scenario AlarmManager would be reliable choice.
– cr...
What happens to a declared, uninitialized variable in C? Does it have a value?
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In practice, they tend to just have some nonsensical value in there initially - some compilers may even put in specific, fixed values to make it obvious when looking in a debugger - but strictly speaking, the compiler is free to do anything from crashing to summoning demons through your nasal pass...
Foreign keys in mongo?
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tupan
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answered Jun 13 '11 at 17:46
NerianNerian
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How to overcome TypeError: unhashable type: 'list'
...used to compare dictionary keys during a dictionary lookup quickly.
Internally, hash() method calls __hash__() method of an object which are set by default for any object.
Converting a nested list to a set
>>> a = [1,2,3,4,[5,6,7],8,9]
>>> set(a)
Traceback (most recent call last...
How to use find command to find all files with extensions from list?
I need to find all image files from directory (gif, png, jpg, jpeg).
9 Answers
9
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When should we use mutex and when should we use semaphore
... to sleep till you release the mutex.
Spinlock:
Use a spinlock when you really want to use a mutex but your thread is not allowed to sleep.
e.g.: An interrupt handler within OS kernel must never sleep. If it does the system will freeze / crash. If you need to insert a node to globally shared linke...