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How expensive is RTTI?
...ource usage in common implementations.
I recently did a bunch of research into RTTI in GCC.
tl;dr: RTTI in GCC uses negligible space and typeid(a) == typeid(b) is very fast, on many platforms (Linux, BSD and maybe embedded platforms, but not mingw32). If you know you'll always be on a blessed plat...
How does a ArrayList's contains() method evaluate objects?
...
ArrayList implements the List Interface.
If you look at the Javadoc for List at the contains method you will see that it uses the equals() method to evaluate if two objects are the same.
...
SQL to determine minimum sequential days of access?
...s OR UserId = 52551
EDIT:
Okay here's my serious answer:
DECLARE @days int
DECLARE @seconds bigint
SET @days = 30
SET @seconds = (@days * 24 * 60 * 60) - 1
SELECT DISTINCT UserId
FROM (
SELECT uh1.UserId, Count(uh1.Id) as Conseq
FROM UserHistory uh1
INNER JOIN UserHistory uh2 ON uh2....
TypeScript or JavaScript type casting
...
How do you indicate to typescript that you have converted an object to another type? For example a func that returns type2, inside it it http gets type 1, does logic to convert, and returns what was type1 but is now type2?
– Tony Gutierrez
...
How to get position of a certain element in strings vector, to use it as an index in ints vector?
...ment in a vector of strings , to use it as an index in another vector of int type, is this possible ?
3 Answers
...
ImageView - have height match width?
... Library 26.0.0. This is the new way to do it:
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<ImageView
android:layout_width="wrap_content"
android:layout_height="0dp"
app:layout_c...
Why can't an anonymous method be assigned to var?
...
Others have already pointed out that there are infinitely many possible delegate types that you could have meant; what is so special about Func that it deserves to be the default instead of Predicate or Action or any other possibility? And, for la...
Syntax of for-loop in SQL Server
...
It interesting to note the the MS documentation is wrong here, really. WHILE doesn't take a boolean expression - it takes a predicate - which in addition to being able to evaluate to TRUE or FALSE, could also be UNKNOWN.
...
What does “yield break;” do in C#?
...unction as an iterator, the body of the function may look like this:
for (int i = 0; i < 5; i++)
{
yield return i;
}
Console.Out.WriteLine("You will see me");
Note that after the loop has completed all its cycles, the last line gets executed and you will see the message in your console ap...
Why should I use var instead of a type? [duplicate]
...
I don't agree with this point at all - the compiler may generate the same bytecode for both but from a code readability/maintenance point of view surely its better for variables to be clearly typed - it avoids ambiguity and makes it clearer to read an...