I presume it outputs ‘byte’, much to this C++ programmer’s surprise.

You learn something every day.

That’s a reasonable assumption, but it’s not the way C# works. See part 6.1.8 of the spec. The key is that if the int is a const, the compiler will look at the value of the int and make sure it fits in the byte. If the int is small enough to fit, then the compiler does the implicit conversion without warnings or errors.

By the way, you can test it with numeric literals as well, and the bug also exists that way.

true?(int)a:(short)b; // is of type int

true?(int)a:(byte)b; // is of type int

Whether a is type byte or b is type int is immaterial.

Are you sure that, despite being a shortening, const int to byte is an implicit conversion (for variables, not numeric literals)? That would surprise me.

const int x=1;
byte b=x; // No shortening warning?

true?x:b; // I’d expect this to have type int – I wouldn’t expect an error because the numeric literal/value held/represented by x could assign/initialise without warning to a byte.

All Software Patents need to be invalidated.

If what you state did hold any truth, this would mean that any implementation of any standard would not be protected by those arrangements by simply having a bug.

Let’s not forget that Microsoft holds patents on HTML, TCP, IPv4 and all sort of XML spec. Last time I checked, all browsers had some sort of non-standard behavior.

Everyone agrees that the Community Promise is not the nirvana of patent safety, but arguing that by not been so it worsen the situation or constitutes a threat is a bit too exaggerated.

I find it hard to follow that by been under the CP, mono is actually less safe against MS than any other software that is not.

All I’m saying is that conforming to the .NET implementation instead of the spec has the potential to create more surface area for a lawsuit, so conforming to the spec is safer. It’s perfectly reasonable to assume that a compiler bug might be in patented code, which might create some legal uncertainty. Whether or not Microsoft would choose to act on that is a completely separate matter and I suspect they wouldn’t want to do so.