## digitalmars.D.bugs - [Issue 3947] New: Implicit and explicit casting of floating point to bool produces different results

- d-bugmail puremagic.com (37/37) Mar 13 2010 http://d.puremagic.com/issues/show_bug.cgi?id=3947

http://d.puremagic.com/issues/show_bug.cgi?id=3947 Summary: Implicit and explicit casting of floating point to bool produces different results Product: D Version: 2.041 Platform: x86 OS/Version: Windows Status: NEW Severity: normal Priority: P2 Component: DMD AssignedTo: nobody puremagic.com ReportedBy: crimson.magus gmail.com --- Comment #0 from Aldo Nunez <crimson.magus gmail.com> 2010-03-13 01:50:09 PST --- Created an attachment (id=587) test case with comments I've observed that these are the rules for explicitly casting floating point numbers to bool: - finite real numbers > -1 and < 1 are false - all other real number values are true (including NaN) - all imaginary numbers are false, since their real part is 0 - complex numbers as bool are the same as their real part as bool I've noticed that the rules for implicitly casting floating point numbers to bool, as in the expression (a && b), is different in several ways: - real 0 and -0 are false - all other finite real numbers > -1 and < 1 are *true* - all other real number values are true (including NaN) - imaginary 0 and -0 are false - finite imaginary numbers > -1 and < 1 are *true* - all other real number values are *true* (including NaN) - complex numbers as bool are the same as the real *or* imaginary part as bool under this new scheme. If either evaluates to true, then the complex is true. There should be a single set of rules used for both cases. As it is, I don't know which part of each set is right. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------

Mar 13 2010