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What is the difference between ? and Object in Java generics?
...n't know the type of the value (it's ?), you don't know if if it's safe to call put(key, "x"), put(key, 0), or anything else.
– erickson
Jan 26 '16 at 19:50
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When is an interface with a default method initialized?
...nough to trigger the initialization. The default method doesn't have to be called or overridden or even mentioned, nor does the presence of an abstract method trigger initialization.
My speculation is that the HotSpot implementation wanted to avoid adding class/interface initialization checking int...
Compare two DataFrames and output their differences side-by-side
...n [24]: changed = ne_stacked[ne_stacked]
In [25]: changed.index.names = ['id', 'col']
In [26]: changed
Out[26]:
id col
1 score True
2 isEnrolled True
Comment True
dtype: bool
Here the first entry is the index and the second the columns which has been changed.
In [27]: ...
How do I access my SSH public key?
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cat ~/.ssh/id_rsa.pub or cat ~/.ssh/id_dsa.pub
You can list all the public keys you have by doing:
$ ls ~/.ssh/*.pub
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Enums and Constants. Which to use when?
...lass with const strings that looks and acts like an enum but circumvents a call to ToString()? Example
– Sinjai
Jan 29 '18 at 0:28
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Iterate over object keys in node.js
... but ... why on earth show the key of the object being passed as something called "element", and the enumerator for the keys array called "key" ?! Can I suggest you update your code sample to use Object.keys(myObject).forEach(function(key, index, arrayOfKeys) {
– Andy Lorenz
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What's the most efficient test of whether a PHP string ends with another string?
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3 function calls overhead doesn't make it fastest.
– Thanh Trung
Dec 10 '19 at 23:02
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Android: What is android.R.id.content used for?
Anybody could explain the meaning of "android.R.id.content" ?
3 Answers
3
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boost::flat_map and its performance compared to map and unordered_map
...se, because your cache will not be warm, and your operation will likely be called just once. Therefore you need to benchmark using RDTSC, and time stuff calling them once only.
Intel has made a paper describing how to use RDTSC (using a cpuid instruction to flush the pipeline, and calling it at leas...
Union Vs Concat in Linq
...nces of items. Your items have different references, thus they all are considered different. When you cast to base type X, reference is not changed.
If you will override Equals and GetHashCode (used to select distinct items), then items will not be compared by reference:
class X
{
public int I...