Re: [Cppunit-devel] CPPUNIT_ASSERT_DOUBLES_EQUAL() with non-finite numbers

[CppUnit d. m. l. <cpp...@li...>]

CppUnit development mailing list wrote:
> Contrary to the claim of Baptiste in the latter patch, isnan()
> is standard: it is part of C99.  Hopefully we can assume it is
> portable by now.
> My patch (below) uses isfinite() instead, which is also from C99.

C99 is non-standard in the context of C++, which is a superset of C90.
So, all C++ compilers might not support this.

I've understood that there is a new C++ standard in the works
(or is it out already), which is supposed to be a superset of C99.
Of course using that is not exactly portable, especially with older
compilers.


> First, here are additional test cases to nail down the semantics of CPPUNIT_ASSERT_DOUBLES:
>  - NaN is not equal to anything, not even to another NaN
>  - infinity is equal to infinity

Remember the sign in infinity.

Why not then compare NaNs with (maybe with volatile x):
if(x == x) { /* not NaN */ }

Don't know about portable infinity test, though?


-- 
Tuomo