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When to use Cast() and Oftype() in Linq
...ly the elements that can safely be cast to type x.
Cast - will try to cast all the elements into type x. if some of them are not from this type you will get InvalidCastException
EDIT
for example:
object[] objs = new object[] { "12345", 12 };
objs.Cast<string>().ToArray(); //throws InvalidCas...
Is there a simple, elegant way to define singletons? [duplicate]
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I don't really see the need, as a module with functions (and not a class) would serve well as a singleton. All its variables would be bound to the module, which could not be instantiated repeatedly anyway.
If you do wish to use a cla...
Create a variable name with “paste” in R?
...oss: a <- rnorm(1); a - eval(parse(text=paste(a))) does not return 0 usually.
– user10307643
Oct 7 '19 at 13:31
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performSelector may cause a leak because its selector is unknown
...for the C function pointer for the method corresponding to the controller. All NSObjects respond to methodForSelector:, but you can also use class_getMethodImplementation in the Objective-C runtime (useful if you only have a protocol reference, like id<SomeProto>). These function pointers are ...
Xml configuration versus Annotation based configuration [closed]
...nformation. But if you like JPA (I don't have any expirience with it), by all means, go for it.
In general:
If an annotation provides functionality and acts as a comment in and of itself, and doesn't tie the code down to some specific process in order to function normally without this annotation, ...
Get all unique values in a JavaScript array (remove duplicates)
...l loop through the array and leave only those entries that pass the given callback function onlyUnique.
onlyUnique checks, if the given value is the first occurring. If not, it must be a duplicate and will not be copied.
This solution works without any extra library like jQuery or prototype.js.
It w...
If I revoke an existing distribution certificate, will it mess up anything with existing apps?
...er weeks of trying to get the guy who has the key to sign the app, they finally came back and said, "Just get it done!". So I am wondering how to proceed. If I go into the provisioning portal, and revoke the dist certificate, and then re-assign one, will I then be able to sign the app and upload it ...
Why is auto_ptr being deprecated?
...cs and the magic of rvalue references, it can do so considerably more naturally. It also "fits" with the rest of the standard library considerably better (though, in fairness, some of that is thanks to the rest of the library changing to accommodate move semantics instead of always requiring copying...
Unique combination of all elements from two (or more) vectors
I am trying to create a unique combination of all elements from two vectors of different size in R.
5 Answers
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What is LDAP used for?
...e extremely fast read/query performance for a large scale of dataset. Typically you want to store only a small piece of information for each entry. The add/delete/update performance is relatively slower compared with read/query because the assumption is that you don’t do “update” that often.
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