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How to get the first non-null value in Java?
Is there a Java equivalent of SQL's COALESCE function? That is, is there any way to return the first non-null value of several variables?
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What is the difference between List (of T) and Collection(of T)?
I've seen them used in a lot of the same ways, and I am worried I'm about to go down a path in design that is irreversible if I don't understand this better. Also, I am using .NET.
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How does std::forward work? [duplicate]
I know what it does and when to use it but I still can't wrap my head around how it works. Please be as detailed as possible and explain when std::forward would be incorrect if it was allowed to use template argument deduction.
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Are there pronounceable names for common Haskell operators? [closed]
I'm reading Learn You a Haskell for Great Good , and I never know how to pronounce the Haskell operators. Do they have "real" names? ?
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What does denote in C# [duplicate]
I'm new to C# and directly diving into modifying some code for a project I received. However, I keep seeing code like this :
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Wrap a delegate in an IEqualityComparer
Several Linq.Enumerable functions take an IEqualityComparer<T> . Is there a convenient wrapper class that adapts a delegate(T,T)=>bool to implement IEqualityComparer<T> ? It's easy enough to write one (if your ignore problems with defining a correct hashcode), but I'd like to know...
boost Composite keys - C/C++ - 清泛网 - 专注C/C++及内核技术
boost Composite keysComposite keysIn relational databases, composite keys depend on two or more fields of a given table The analogous concept in Boost MultiIndex is Composite keys
In relational databases, composite keys depend on two or more fields of a given table. The analogous concept in Boos...
LINQ Select Distinct with Anonymous Types
So I have a collection of objects. The exact type isn't important. From it I want to extract all the unique pairs of a pair of particular properties, thusly:
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Fixed size queue which automatically dequeues old values upon new enques
I'm using ConcurrentQueue for a shared data structure which purpose is holding the last N objects passed to it (kind of history).
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How to emulate C array initialization “int arr[] = { e1, e2, e3, … }” behaviour with std::array?
(Note: This question is about not having to specify the number of elements and still allow nested types to be directly initialized.)
This question discusses the uses left for a C array like int arr[20]; . On his answer , @James Kanze shows one of the last strongholds of C arrays, it's unique i...