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How to list all the available keyspaces in Cassandra?
I am newbie in Cassandra and trying to implement one toy application using Cassandra. I had created one keyspace and few column families in my Cassandra DB but I forgot the name of my cluster.
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How to wait for several Futures?
Suppose I have several futures and need to wait until either any of them fails or all of them succeed.
8 Answers
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unsigned APK can not be installed
...people for testing.
I have installed it on my Desire directly from eclipse and it works fine.
7 Answers
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Python constructors and __init__
Why are constructors indeed called "Constructors"? What is their purpose and how are they different from methods in a class?
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What character encoding should I use for a HTTP header?
...e http://html5boilerplate.com/ for more info) for a Server HTTP-header and am wondering if it is "allowed" per spec.
2 ...
Do fragments really need an empty constructor?
... constructor anyway. You should have a newInstance() static method defined and pass any parameters via arguments (bundle)
For example:
public static final MyFragment newInstance(int title, String message) {
MyFragment f = new MyFragment();
Bundle bdl = new Bundle(2);
bdl.putInt(EXTRA_T...
Set operations (union, intersection) on Swift array?
Are there any standard library calls I can use to either perform set operations on two arrays, or implement such logic myself (ideally as functionally and also efficiently as possible)?
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How to check if PHP array is associative or sequential?
...kurO.
For the second question (checking whether the array is zero-indexed and sequential), you can use the following function:
function isAssoc(array $arr)
{
if (array() === $arr) return false;
return array_keys($arr) !== range(0, count($arr) - 1);
}
var_dump(isAssoc(['a', 'b', 'c'])); //...
What's the difference between std::move and std::forward
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std::move takes an object and allows you to treat it as a temporary (an rvalue). Although it isn't a semantic requirement, typically a function accepting a reference to an rvalue will invalidate it. When you see std::move, it indicates that the value ...
The cast to value type 'Int32' failed because the materialized value is null
...ky abstraction" that yields unexpected behaviour.
One such case is null handling, where there can be unexpected nulls in different places. ...DefaultIfEmpty(0).Sum(0) can help in this (quite simple) case, where there might be no elements and sql's SUM returns null whereas c# expect 0.
A more gene...