use Benchmark qw {:all};
use 5.016;

my %hash;

#  set up the hash
for (1001..2000) {
    $hash{$_}++;
}
#  two keys we use below
our $key1 = 1001;
our $key2 = 1002;
#  hash key 1 is SV
$hash{$key1} = 1;
#  hash key 2 is RV
$hash{$key2} = {1..10};

#  assign to global as a baseline
our $xx_global;

#  keys are short so the timing table is not too wide
#  char  1:   e  = exists check, 
#             v  = value check
#  chars 2,3: ck = constant key, 
#             vk = variable key
#  chars 4,5: sv = key contains scalar value, 
#             rv = key contains reference
#  char  6:   l  = assign to lexical, 
#             g  = assign to global
#  thus
#  ecksvl means "exists check 
#                using constant key 
#                containing a scalar value, 
#                assigned to lexical"
#  (the value is clearly redundant for an exists check, 
#   but is retained for completeness)

my %checks = (
    ecksvl => 'my $x = exists $hash{1001}',
    evksvl => 'my $x = exists $hash{$key1}',
    vcksvl => 'my $x = $hash{1001}',
    vvksvl => 'my $x = $hash{$key1}',
    evksvg => '$xx_global = exists $hash{$key1}',
    vvksvg => '$xx_global = $hash{$key1}',
    eckrvl => 'my $x = exists $hash{1002}',
    evkrvl => 'my $x = exists $hash{$key2}',
    vckrvl => 'my $x = $hash{1002}',
    vvkrvl => 'my $x = $hash{$key2}',
    evkrvg => '$xx_global = exists $hash{$key2}',
    vvkrvg => '$xx_global = $hash{$key2}',
);


cmpthese (
    -3,
    \%checks
);