use strict;
use warnings;

use Benchmark qw( cmpthese );

my $as = 'a' x 100;

sub c_dq {
  eval "\$a = \"$as\";";
}

sub c_sq {
  eval "\$a = '$as';";
}

eval "sub r_dq { \$a = \"$as\"; }";

eval "sub r_sq { \$a = '$as'; }";

print("Compile-time difference\n");

cmpthese(-3, {
   double => \&c_dq,
   single => \&c_sq,
});

print("Run-time difference\n");

cmpthese(-3, {
   double => \&r_dq,
   single => \&r_sq,
});