Not sure if I'm understanding correctly what you're intending to do, but if the idea is to force the argument to write (i.e. { 42 }) to be handled as a coderef (without having to say sub {...}), using Exporter works for me:

( A.pm )

package A;

use subs qw(write);  # only needed if you want to call write {...} wit
+hin package A itself
use Exporter 'import';
@EXPORT_OK = qw(write);

sub write (&) { printf "write(): $_[0] -> %s\n", $_[0]->() }
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used as

package B;

use A 'write';

write { 42 };
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would treat { 42 } as a sub, and print out

write(): CODE(0x65eb80) -> 42
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