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Different floating point result with optimization enabled - compiler bug?

... I think this is the answer. The constant 4.55 gets converted to 4.54999999999999 which is the closest binary representation in 64 bits; multiply by 10 and round again to 64 bits and you get 45.5. If you skip the rounding step by keeping it in an 80-bit register you end up wit...
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How to get first and last day of previous month (with timestamp) in SQL Server

... First Day Of Current Week. select CONVERT(varchar,dateadd(week,datediff(week,0,getdate()),0),106) Last Day Of Current Week. select CONVERT(varchar,dateadd(week,datediff(week,0,getdate()),6),106) First Day Of Last week. select CONVERT(varchar,DATEADD(wee...
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Is the Scala 2.8 collections library a case of “the longest suicide note in history”? [closed]

...then further generalized by only requiring that a function exists that can convert the result to whatever data structure the user wants: map :: IterableLike i ⇒ (a → b) → i → ([b] → c) → c I admit that the syntax is a bit clunkier, but the semantics are the same. Basically, it starts ...
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Why does Stream not implement Iterable?

... To convert a Stream to an Iterable, you can do Stream<X> stream = null; Iterable<X> iterable = stream::iterator To pass a Stream to a method that expects Iterable, void foo(Iterable<X> iterable) simply ...
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Double not (!!) operator in PHP

...It means if $row has a truthy value, it will return true, otherwise false, converting to a boolean value. Here is example expressions to boolean conversion from php docs. Expression Boolean $x = ""; FALSE $x = null; FALSE var $x; FALSE $x is und...
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How to initialize std::vector from C-style array?

...aster than it looks. template<typename T, size_t N> vector<T> convert_array_to_vector(const T (&source_array)[N]) { return vector<T>(source_array, source_array+N); } share | ...
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Which are more performant, CTE or temporary tables?

...en with two CTEs in SQL server. It was taking 28sec. I spent two minutes converting them to temp tables and the query took 3 seconds I added an index to the temp table on the field it was being joined on and got it down to 2 seconds Three minutes of work and now its running 12x faster all by rem...
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Difference between string and char[] types in C++

... and certain functions may only accept a string as input, requiring you to convert the array to a string. It's better to use strings, they were made so that you don't have to use arrays. If arrays were objectively better we wouldn't have strings. ...
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Case objects vs Enumerations in Scala

...ceVal(character: Char, pointValue: Int) extends super.Val() implicit def convert(value: Value) = value.asInstanceOf[ChessPieceVal] } The following items from the enumeration definition are not available (happens to be identical to the list for directly using the Java Enum): 3.1 - It would be...
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Is multiplication and division using shift operators in C actually faster?

...upport fast multiplication (and most didn't back then), the compiler would convert the multiplication into the appropriate combinations of shifts and add/sub. And because it knew the final goal, it could sometimes do so in less instructions than when you explicitly wrote the shifts and the add/subs...