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What are the differences between type() and isinstance()?
...identity of types and rejects instances of subtypes, AKA subclasses).
Normally, in Python, you want your code to support inheritance, of course (since inheritance is so handy, it would be bad to stop code using yours from using it!), so isinstance is less bad than checking identity of types because...
Locking pattern for proper use of .NET MemoryCache
...t collection that has thread safe reads but non-thread safe writes (almost all of classes under the System.Collections namespace is like that).
Here is how I would do it using ReaderWriterLockSlim to protect access. You need to do a kind of "Double Checked Locking" to see if anyone else created the...
Make a negative number positive
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Note the edge cases, e.g. Math.abs(Integer.MIN_VALUE) = Integer.MIN_VALUE.
– Zach Scrivena
Jan 30 '09 at 0:24
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When to use generic methods and when to use wild-card?
...eed such kind of relation, then you are free not to use type parameters at all.
Some other difference between using wildcards and type parameters are:
If you have only one parameterized type argument, then you can use wildcard, although type parameter will also work.
Type parameters support multi...
Which is the fastest algorithm to find prime numbers?
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Actually I don't think primegen is the fastest, or even the second-fastest; yafu and primesieve are both faster in general, I think, and certainly over 2^32. Both are (modified) sieves of Eratosthenes rather than the Atkin-Berns...
iTerm 2: How to set keyboard shortcuts to jump to beginning/end of line?
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I answered my first comment elsewhere, basically hex-code 0x15 gives Ctrl+U which clears the line. However I am finding 0x01 Ctrl+A to interfere with Tmux usage. Therefore I intend to map it instead to the Home key (same functionality as Fn+Left on a Mac keyboard).
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Secure hash and salt for PHP passwords
It is currently said that MD5 is partially unsafe. Taking this into consideration, I'd like to know which mechanism to use for password protection.
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What is the “FS”/“GS” register intended for?
...dows and Linux.
The original intention behind the segment registers was to allow a program to access many different (large) segments of memory that were intended to be independent and part of a persistent virtual store. The idea was taken from the 1966 Multics operating system, that treated files a...
Fastest way to iterate over all the chars in a String
In Java, what would the fastest way to iterate over all the chars in a String, this:
8 Answers
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Possible to do a MySQL foreign key to one of two possible tables?
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What you're describing is called Polymorphic Associations. That is, the "foreign key" column contains an id value that must exist in one of a set of target tables. Typically the target tables are related in some way, such as being instances of some c...