姓名 只读-用于创建只读标量,数组,哈希的工具 概要 use Readonly; # Deep Read-only scalar Readonly::Scalar $sca => $initial_value; Readonly::Scalar my $sca => $initial_value; # Deep Read-only array Readonly::Array @arr => @values; Readonly::Array my @arr => @values; # Deep Read-only hash Readonly::Hash %has => (key => value, key => value, ...); Readonly::Hash my %has => (key => value, key => value, ...); # or: Re