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I want to get the type of a variable at runtime
...rameter in the previous ClassTag example, but uses an anonymous variable.
One can also get a ClassTag from a value's Class, like this:
val x: Any = 5
val y = 5
import scala.reflect.ClassTag
def f(a: Any, b: Any) = {
val B = ClassTag(b.getClass)
ClassTag(a.getClass) match {
case B => "a ...
What are the details of “Objective-C Literals” mentioned in the Xcode 4.4 release notes?
.../objective-c-literals-for-nsdictionary-nsarray-and:
Objective-C literals: one can now create literals for NSArray, NSDictionary, and NSNumber (just like one can create literals for NSString)
NSArray Literals
Previously:
array = [NSArray arrayWithObjects:a, b, c, nil];
Now:
array = @[ a, b, c ...
dplyr summarise: Equivalent of “.drop=FALSE” to keep groups with zero length in output
...nt>
#> 1 1 6
#> 2 2 6
#> 3 3 0
One additional note to go with @Moody_Mudskipper's answer: Using .drop=FALSE can give potentially unexpected results when one or more grouping variables are not coded as factors. See examples below:
library(dplyr)
data(iris)...
Nginx no-www to www and www to no-www
...ill get the http protocol
# and 301 is best practice for tablet, phone, desktop and seo
return 301 $scheme://domain.com$request_uri;
}
server {
listen 80;
server_name domain.com;
# here goes the rest of your config file
# example
location / {...
What is the recommended approach towards multi-tenant databases in MongoDB?
...h I found this article on mongodb support site (way back added since it's gone):
https://web.archive.org/web/20140812091703/http://support.mongohq.com/use-cases/multi-tenant.html
The guys stated to avoid 2nd options at any cost, which as I understand is not particularly specific to mongodb. My impr...
Why '&&' and not '&'?
...ase.
A similar but simpler example of this is the following code (as mentioned by TJHeuvel):
if(op != null && op.CanExecute())
{
// Do Something
}
CanExecute is only executed if op is not null. If op is null, the first part of the expression (op != null) evaluates to false and the ev...
Why shouldn't I use PyPy over CPython if PyPy is 6.3 times faster?
...u made, and when you understand the difference, you'll understand at least one set of reasons why you can't just say "use PyPy". It might sound like I'm nit-picking, but understanding why these two statements are totally different is vital.
To break that down:
The statement they make only applies...
Object reference not set to an instance of an object.Why doesn't .NET show which object is `null`?
...t when the first argument on the evaluation stack is a null reference (the one that was loaded using ldloc.0).
If .NET should be able to tell that it was s that was a null reference it should in some way track that the first argument on the evaluation stack originated form s. In this case it is eas...
Python __str__ versus __unicode__
...to be consistent. Are there specific rules when it is better to implement one versus the other? Is it necessary/good practice to implement both?
...
Browsers' default CSS for HTML elements
...embed }
li { display: list-item }
head { display: none }
table { display: table }
tr { display: table-row }
thead { display: table-header-group }
tbody { display: table-row-group }
tfoot { display: table-footer-group }
col ...