My first test gets me a segmentation fault, so I'm not sure...

perl -M'Data::Dimensions qw(:extended &units)' -E'say add( "1.2G", "50
+0M"); \
sub add \
  { my $sum= units( { byte => 0 }); \
    foreach (@_) { $sum += $_ } \
    return  $sum; \
  }\
'
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