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Questions tagged [lifted-operators]

Lifted operators are operators which work over nullable types by "lifting" the operators which already exist on the non-nullable form.

Lifted operators are operators which work over nullable types by "lifting" the operators which already exist on the non-nullable form.

The answer What are lifted operators is a good overview with additional references.

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What are lifted operators?

I was looking at this article and am struggling to follow the VB.NET example that explains lifted operators. There doesn't seem to be an equivalent C# example or tutorial. I don't have much experience with operator overloading in general, so trying…
fletcher
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Why are there no lifted short-circuiting operators on `bool?`?

Why doesn't bool? support lifted && and ||? They could have lifted the true and false operators which would have indirectly added lifted && and ||. The operators | and & are already lifted and implement the correct Three-valued logic. But of course…
CodesInChaos
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Wrong compiler warning when comparing struct to null

Consider the following code: DateTime t = DateTime.Today; bool isGreater = t > null; With Visual Studio 2010 (C# 4, .NET 4.0), I get the following warning: warning CS0458: The result of the expression is always 'null' of type 'bool?' This is…
Jeppe Stig Nielsen
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Curious overload resolution when using a naked null literal with user-defined operators

(The "user-defined" in the title refers to the fact that addition and subtraction of TimeSpan and DateTime are not a part of the C# standard. They are defined in the BCL.) Playing around with lifted operators on nullable TimeSpan and DateTime…
Jeppe Stig Nielsen
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System.Nullable What is the value of null * int value?

Consider the following statements: int? v1 = null; int? v2 = 5 * v1; What is the value of v2? (null or empty string?) How can I prevent the compiler to mark it as invalid operation? Do I need to follow custom exception handling?
user160677
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Comparing two null nullables

The C# 5.0 spec reads in chapter 7.1.3 https://msdn.microsoft.com/en-us/library/ms228593.aspx The lifted operator produces the value false if one or both operands are null. However testing and also this MSDN link…
Dee J. Doena
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Do lifted operators on nullable value types employ short-circuiting?

I wonder whether code like this should execute GetAnotherValue()? int? x1 = null; var check = x1 <= GetAnotherValue(); I assume it shouldn't since that sounds more reasonable to me. But I'm not sure if this is guaranteed. As far as I can find, the…
relatively_random
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