On Monday, 20 August 2012 at 19:28:33 UTC, Peter Alexander wrote:
[cut]
The problem is that it's easy for even NaN's to be filtered out.
float x = 0.0f;
float y; // oops
float z = min(x, y); // NaN has disappeared, unnoticed!
In theory, one could prevent this by setting the floating point
control word to trigger a trap when reading a NaN which I think
*should* be the default.
Unfortunately it doesn't seem to work, there is an FPE in the
code below, where it shouldn't.
Then again, the online compiler I've tried is very old: dmd-2.042.
import std.stdio, std.math, std.algorithm;
int main()
{
FloatingPointControl fpc;
fpc.enableExceptions(FloatingPointControl.severeExceptions);
float x = 0.0f;
float y; // oops
y=1;
float z = min(x, y);
writeln("min x,y=",z);
return 0;
}
<<
