in reply to Re^3: Looking for testers who use Microsoft compilers
in thread Looking for testers who use Microsoft compilers

I only have installed Visual studio 2017 and 2019 on my server

I was expecting that a perl built with Visual Studio 2017 would report a $Config{ccversion} that was less than '19.24.28316' and greater than '16.00.30319.01'. (My guess is that with Visual Studio 2017, $Config{ccversion} would begin with 19.1...)
I thought that '19.24.28316' identifies Visual Studio 2019 and that '16.00.30319.01' identifies Visual Studio 2010.

Anyway, if you have a perl (whose ivsize is 8) that has been built with that Visual Studio 2017 compiler, and could test List::Uniqnum that would be handy.
Or, alternatively, just provide the output of perl -le "printf '%0.20g', 18446744073709549568;".
That output will also tell me whether '%0.20g' formatting is reliable or not - and the thing I'm trying to work out is at which version of the Microsoft compilers did '%0.20g' become reliable.
If it outputs 18446744073709549568, then '%0.20g' formatting is fine ... but not so if it outputs 18446744073709550000.