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What is the difference between a var and val definition in Scala?
... can, then, go the other direction. If val is that better, why have var at all? Well, some languages did take that route, but there are situations in which mutability improves performance, a lot.
For example, take an immutable Queue. When you either enqueue or dequeue things in it, you get a new Qu...
Unable to begin a distributed transaction
...S DTC will not be able to communicate
with each other. This problem typically occurs if one of the systems
were cloned using unsupported cloning tools. MS DTC requires that the
systems be cloned using supported cloning tools such as SYSPREP.
Running 'msdtc -uninstall' and then 'msdtc -instal...
Visual Studio, debug one of multiple threads
...pping through a single thread seems to be mostly fixed in VS 2012" - not really, it's still broken in VS2017.
– user626528
Jan 25 '18 at 22:46
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Replacing blank values (white space) with NaN in pandas
I want to find all values in a Pandas dataframe that contain whitespace (any arbitrary amount) and replace those values with NaNs.
...
echo that outputs to stderr
...criptors will refer to the same file: the one file descriptor #2 was originally referring to. For more information see the Bash Hackers Illustrated Redirection Tutorial.
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How can I concatenate NSAttributedStrings?
...
NSMutableAttributedString *mutableAttString = [[NSMutableAttributedString alloc] init];
NSString *plainString = // ...
NSDictionary *attributes = // ... a dictionary with your attributes.
NSAttributedString *newAttString = [[NSAttributedString alloc] initWithString:plainString attributes:attribute...
Determine which MySQL configuration file is being used
...inux, then start the 'mysqld' with strace, for eg strace ./mysqld.
Among all the other system calls, you will find something like:
stat64("/etc/my.cnf", 0xbfa3d7fc) = -1 ENOENT (No such file or directory)
stat64("/etc/mysql/my.cnf", {st_mode=S_IFREG|0644, st_size=4227, ...}) = 0
open("/etc/...
Getting Chrome to accept self-signed localhost certificate
...tificate for the localhost CN. Firefox accepts this certificate after initially complaining about it, as expected. Chrome and IE, however, refuse to accept it, even after adding the certificate to the system certificate store under Trusted Roots. Even though the certificate is listed as correctly in...
How to flatten tree via LINQ?
...lt;T>> f
) => e.SelectMany(c => f(c).Flatten(f)).Concat(e);
Call this function like this:
IEnumerable<MyNode> tree = ....
var res = tree.Flatten(node => node.Elements);
If you would prefer flattening in pre-order rather than in post-order, switch around the sides of the Con...
How to “undelete” a deleted folder in Subversion / TortoiseSVN?
We have accidentally deleted the 'tags' folder from our Subversion repository where we only intended to delete one specific tag. What is the easiest way to get the 'tags' folder back?
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