> On Apr 17, 2017, at 9:07 AM, Joe Groff via swift-evolution 
> <[email protected]> wrote:
> 
> 
>> On Apr 15, 2017, at 9:49 PM, Xiaodi Wu via swift-evolution 
>> <[email protected]> wrote:
>> 
>> For example, I expect `XCTAssertEqual<T : FloatingPoint>(_:_:)` to be vended 
>> as part of XCTest, in order to make sure that 
>> `XCTAssertEqual(resultOfComputation, Double.nan)` always fails.
> 
> Unit tests strike me as an example of where you really *don't* want level 1 
> comparison semantics. If I'm testing the output of an FP operation, I want to 
> be able to test that it produces nan when I expect it to, or that it produces 
> the right zero.

I find it very concerning that == will have different results based on concrete 
vs generic type parameters.  This can only lead to significant confusion down 
the road.  I’m highly concerned about situations where taking a concrete 
algorithm and generalizing it (with generics) will change its behavior.

-Chris

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