[perl #36689] &=, |= and ^= overloads are nbot documented

From: "Adriano Rodrigues" <a.r.ferreira@gmail.com>
Message-ID: <73ddeb6c0611231143y1e3461dbqf30f5fce16698b5c@mail.gmail.com>

p4raw-id: //depot/perl@29373

diff --git a/lib/overload.pm b/lib/overload.pm
index 690be22..1ca22b4 100644 (file)
--- a/lib/overload.pm
+++ b/lib/overload.pm
@@ -117,7 +117,7 @@ sub mycan {                         # Real can would leave stubs.
         num_comparison   => "< <= >  >= == !=",
         '3way_comparison'=> "<=> cmp",
         str_comparison   => "lt le gt ge eq ne",
-        binary           => "& | ^",
+        binary           => '& &= | |= ^ ^=',
         unary            => "neg ! ~",
         mutators         => '++ --',
         func             => "atan2 cos sin exp abs log sqrt int",
@@ -350,13 +350,17 @@ arrays, C<cmp> is used to compare values subject to C<use overload>.
 
 =item * I<Bit operations>
 
-    "&", "^", "|", "neg", "!", "~",
+    "&", "&=", "^", "^=", "|", "|=", "neg", "!", "~",
 
 C<neg> stands for unary minus.  If the method for C<neg> is not
 specified, it can be autogenerated using the method for
 subtraction. If the method for C<!> is not specified, it can be
 autogenerated using the methods for C<bool>, or C<"">, or C<0+>.
 
+The same remarks in L<"Arithmetic operations"> about
+assignment-variants and autogeneration apply for
+bit operations C<"&">, C<"^">, and C<"|"> as well.
+
 =item * I<Increment and decrement>
 
     "++", "--",
@@ -437,7 +441,7 @@ A computer-readable form of the above table is available in the hash
  num_comparison          => '< <= > >= == !=',
  '3way_comparison'=> '<=> cmp',
  str_comparison          => 'lt le gt ge eq ne',
- binary                  => '& | ^',
+ binary                  => '& &= | |= ^ ^=',
  unary           => 'neg ! ~',
  mutators        => '++ --',
  func            => 'atan2 cos sin exp abs log sqrt',

diff --git a/lib/overload.t b/lib/overload.t
index 6dafa07..ade87f2 100644 (file)
--- a/lib/overload.t
+++ b/lib/overload.t
@@ -47,7 +47,7 @@ sub numify { 0 + "${$_[0]}" } # Not needed, additional overhead
 package main;
 
 $| = 1;
-use Test::More tests => 509;
+use Test::More tests => 512;
 
 
 $a = new Oscalar "087";
@@ -1253,3 +1253,36 @@ foreach my $op (qw(<=> == != < <= > >=)) {
     undef $obj;
     is ($ref, undef);
 }
+
+{
+    package bit;
+    # bit operations have overloadable assignment variants too
+
+    sub new { bless \$_[1], $_[0] }
+
+    use overload
+          "&=" => sub { bit->new($_[0]->val . ' & ' . $_[1]->val) }, 
+          "^=" => sub { bit->new($_[0]->val . ' ^ ' . $_[1]->val) },
+          "|"  => sub { bit->new($_[0]->val . ' | ' . $_[1]->val) }, # |= by fallback
+          ;
+
+    sub val { ${$_[0]} }
+
+    package main;
+
+    my $a = bit->new(my $va = 'a');
+    my $b = bit->new(my $vb = 'b');
+
+    $a &= $b;
+    is($a->val, 'a & b', "overloaded &= works");
+
+    my $c = bit->new(my $vc = 'c');
+
+    $b ^= $c;
+    is($b->val, 'b ^ c', "overloaded ^= works");
+
+    my $d = bit->new(my $vd = 'd');
+
+    $c |= $d;
+    is($c->val, 'c | d', "overloaded |= (by fallback) works");
+}