The current set of warning checks enabled by the use warnings
pragma. It has the same scoping as the $^H
and %^H
variables. The exact values are considered internal to the warnings pragma and may change between versions of Perl.
Each time a statement completes being compiled, the current value of ${^WARNING_BITS}
is stored with that statement, and can later be retrieved via (caller($level))[9]
.
This variable was added in Perl v5.6.0.