sub numify { 0 + "${$_[0]}" } # Not needed, additional overhead
# comparing to direct compilation based on
# stringify
+sub import {
+ shift;
+ return unless @_;
+ die "unknown import: @_" unless @_ == 1 and $_[0] eq ':constant';
+ overload::constant integer => sub {Math::BigInt->new(shift)};
+}
$zero = 0;
'1 23 456 7890' canonical value '+1234567890'
+=head1 Autocreating constants
+
+After C<use Math::BigInt ':constant'> all the integer decimal constants
+in the given scope are converted to C<Math::BigInt>. This convertion
+happens at compile time.
+
+In particular
+
+ perl -MMath::BigInt=:constant -e 'print 2**100'
+
+print the integer value of C<2**100>. Note that without convertion of
+constants the expression 2**100 will be calculatted as floating point number.
+
=head1 BUGS
The current version of this module is a preliminary version of the