CODEWITHSUNDEEP
c#doubleconstants
Berryl
Berryl

Reputation: 12833

how does const declaration set to itself work

This is the declaration for PositiveInfinity in Double. 

/// <summary>
/// Represents positive infinity. This field is constant.
/// </summary>
/// <filterpriority>1</filterpriority>
public const double PositiveInfinity = double.PositiveInfinity;

This looks like a cycle that wouldn't pass the compiler... why is it declared this way & how does this work?

Upvotes: 2

Views: 214

Answers (1)

Eric Lippert
Eric Lippert

Reputation: 659994

This is the declaration for PositiveInfinity in Double.

No, it is not.

This is a portion of the decompilation of the Double struct provided by Resharper.

That's better.

This looks like a cycle that wouldn't pass the compiler.

That's because it is a cycle that would not pass the compiler.

Why does Resharper's decompiler produce code that doesn't compile?

My guess is that it's a bug. You'll have to ask the Resharper team for a definitive answer.

Likely they have a heuristic that says to put Double.PositiveInfinity in anywhere that a positive infinity constant appears; this is perhaps the one place where that's wrong. So that's an easy bug to write.

What does the real declaration look like?

I haven't got reference sources on my home computer, but my guess is that the real declaration is:

public const double PositiveInfinity = 1.0 / 0.0;

Where can I get the reference sources, so I don't have to rely on an unreliable decompiler?

http://referencesource.microsoft.com

Upvotes: 14

Related Questions