In List§

See primary documentation in context for method Bool

method Bool(List:D: --> Bool:D)

Returns True if the list has at least one element, and False for the empty list.

say ().Bool;  # OUTPUT: «False␤» 
say (1).Bool; # OUTPUT: «True␤»

In Capture§

See primary documentation in context for method Bool

method Bool(Capture:D: --> Bool:D)

Returns True if the Capture contains at least one named or one positional argument.

say \(1,2,3, apples => 2).Bool; # OUTPUT: «True␤» 
say \().Bool;                   # OUTPUT: «False␤»

In Failure§

See primary documentation in context for method Bool

multi method Bool(Failure:D: --> Bool:D)

Returns False, and marks the failure as handled.

sub f() { fail };
my $v = f;
say $v.handled; # OUTPUT: «False␤» 
say $v.Bool;    # OUTPUT: «False␤» 
say $v.handled; # OUTPUT: «True␤»

In Match§

See primary documentation in context for method Bool

method Bool(Capture:D: --> Bool:D)

Returns True on successful and False on unsuccessful matches. Please note that any zero-width match can also be successful.

say 'abc' ~~ /^/;                   # OUTPUT: «｢｣␤» 
say $/.from, ' ',  $/.to, ' ', ?$/; # OUTPUT: «0 0 True␤»

In Regex§

See primary documentation in context for method Bool

multi method Bool(Regex:D: --> Bool:D)

Matches against the caller's $_ variable, and returns True for a match or False for no match.

In role Setty§

See primary documentation in context for method Bool

multi method Bool(Setty:D: --> Bool:D)

Returns True if the invocant contains at least one element.

my $s1 = Set.new(1, 2, 3);
say $s1.Bool;                                     # OUTPUT: «True␤» 
 
my $s2 = $s1 ∩ Set.new(4, 5);                     # set intersection operator 
say $s2.Bool;                                     # OUTPUT: «False␤»

In role Baggy§

See primary documentation in context for method Bool

method Bool(Baggy:D: --> Bool:D)

Returns True if the invocant contains at least one element.

my $breakfast = ('eggs' => 1).BagHash;
say $breakfast.Bool;                              # OUTPUT: «True␤» 
                                                  # (since we have one element) 
$breakfast<eggs> = 0;                             # weight == 0 will lead to element removal 
say $breakfast.Bool;                              # OUTPUT: «False␤»

In StrDistance§

See primary documentation in context for method Bool

Returns True if before is different from after.

In Proc§

See primary documentation in context for method Bool

multi method Bool(Proc:D:)

Awaits for the process to finish and returns True if both exit code and signal of the process were 0, indicating a successful process termination. Returns False otherwise.

In Mu§

See primary documentation in context for routine Bool

multi        Bool(Mu --> Bool:D)
multi method Bool(   --> Bool:D)

Returns False on the type object, and True otherwise.

Many built-in types override this to be False for empty collections, the empty string or numerical zeros

say Mu.Bool;                    # OUTPUT: «False␤» 
say Mu.new.Bool;                # OUTPUT: «True␤» 
say [1, 2, 3].Bool;             # OUTPUT: «True␤» 
say [].Bool;                    # OUTPUT: «False␤» 
say %( hash => 'full' ).Bool;   # OUTPUT: «True␤» 
say {}.Bool;                    # OUTPUT: «False␤» 
say "".Bool;                    # OUTPUT: «False␤» 
say 0.Bool;                     # OUTPUT: «False␤» 
say 1.Bool;                     # OUTPUT: «True␤» 
say "0".Bool;                   # OUTPUT: «True␤»

In role Numeric§

See primary documentation in context for method Bool

multi method Bool(Numeric:D:)

Returns False if the number is equivalent to zero, and True otherwise.

In Map§

See primary documentation in context for method Bool

method Bool(Map:D: --> Bool:D)

Returns True if the invocant contains at least one key/value pair.

my $m = Map.new('a' => 2, 'b' => 17);
say $m.Bool;                                      # OUTPUT: «True␤»

In Str§

See primary documentation in context for method Bool

method Bool(Str:D: --> Bool:D)

Returns False if the string is empty, True otherwise.

In Allomorph§

See primary documentation in context for method Bool

multi method Bool(::?CLASS:D:)

Returns False if the invocant is numerically 0, otherwise returns True. The Str value of the invocant is not considered.

Note: For the Allomorph subclass RatStr also see Rational.Bool.

In Promise§

See primary documentation in context for method Bool

multi method Bool(Promise:D:)

Returns True for a kept or broken promise, and False for one in state Planned.

In Junction§

See primary documentation in context for method Bool

multi method Bool(Junction:D:)

Collapses the Junction and returns a single Boolean value according to the type and the values it holds. Every element is transformed to Bool.

my $n = Junction.new( "one", 1..6 );
say $n.Bool;                         # OUTPUT: «False␤» 

All elements in this case are converted to True, so it's false to assert that only one of them is.

my $n = Junction.new( "one", <0 1> );
say $n.Bool;                         # OUTPUT: «True␤» 

Just one of them is truish in this case, 1, so the coercion to Bool returns True.

In role Rational§

See primary documentation in context for method Bool

multi method Bool(Rational:D: --> Bool:D)

Returns False if numerator is 0, otherwise returns True. This applies for <0/0> zero-denominator <Rational as well, despite ?<0/0>.Num being True.

In role Blob§

See primary documentation in context for method Bool

multi method Bool(Blob:D:)

Returns False if and only if the buffer is empty.

my $blob = Blob.new();
say $blob.Bool; # OUTPUT: «False␤» 
$blob = Blob.new([1, 2, 3]);
say $blob.Bool; # OUTPUT: «True␤»