More perldelta entries and fixes

[p5sagit/p5-mst-13.2.git] / lib / overload.pm

diff --git a/lib/overload.pm b/lib/overload.pm
index df03679..0120882 100644 (file)
--- a/lib/overload.pm
+++ b/lib/overload.pm
@@ -1,8 +1,6 @@
 package overload;
 
-our $VERSION = '1.01';
-
-$overload::hint_bits = 0x20000; # HINT_LOCALIZE_HH
+our $VERSION = '1.04';
 
 sub nil {}
 
@@ -93,11 +91,7 @@ sub AddrRef {
        return sprintf("$class_prefix$type(0x%x)", $addr);
 }
 
-sub StrVal {
-  (ref $_[0] && OverloadedStringify($_[0]) or ref($_[0]) eq 'Regexp') ?
-    (AddrRef(shift)) :
-    "$_[0]";
-}
+*StrVal = *AddrRef;
 
 sub mycan {                            # Real can would leave stubs.
   my ($package, $meth) = @_;
@@ -153,7 +147,7 @@ sub constant {
     }
     else {
         $^H{$_[0]} = $_[1];
-        $^H |= $constants{$_[0]} | $overload::hint_bits;
+        $^H |= $constants{$_[0]};
     }
     shift, shift;
   }
@@ -174,7 +168,7 @@ __END__
 
 =head1 NAME
 
-overload - Package for overloading perl operations
+overload - Package for overloading Perl operations
 
 =head1 SYNOPSIS
 
@@ -426,7 +420,7 @@ The dereference operators must be specified explicitly they will not be passed t
 
 =item * I<Special>
 
-    "nomethod", "fallback", "=",
+    "nomethod", "fallback", "=", "~~",
 
 see L<SPECIAL SYMBOLS FOR C<use overload>>.
 
@@ -546,6 +540,11 @@ C<"nomethod"> value, and if this is missing, raises an exception.
 B<Note.> C<"fallback"> inheritance via @ISA is not carved in stone
 yet, see L<"Inheritance and overloading">.
 
+=head2 Smart Match
+
+The key C<"~~"> allows you to override the smart matching used by
+the switch construct. See L<feature>.
+
 =head2 Copy Constructor
 
 The value for C<"="> is a reference to a function with three
@@ -667,6 +666,23 @@ value is a scalar and not a reference.
 
 =back
 
+=head1 Minimal set of overloaded operations
+
+Since some operations can be automatically generated from others, there is
+a minimal set of operations that need to be overloaded in order to have
+the complete set of overloaded operations at one's disposal.
+Of course, the autogenerated operations may not do exactly what the user
+expects. See L<MAGIC AUTOGENERATION> above. The minimal set is:
+
+    + - * / % ** << >> x
+    <=> cmp
+    & | ^ ~
+    atan2 cos sin exp log sqrt int
+
+Additionally, you need to define at least one of string, boolean or
+numeric conversions because any one can be used to emulate the others.
+The string conversion can also be used to emulate concatenation.
+
 =head1 Losing overloading
 
 The restriction for the comparison operation is that even if, for example,
@@ -704,7 +720,10 @@ Package C<overload.pm> provides the following public functions:
 
 =item overload::StrVal(arg)
 
-Gives string value of C<arg> as in absence of stringify overloading.
+Gives string value of C<arg> as in absence of stringify overloading. If you
+are using this to get the address of a reference (useful for checking if two
+references point to the same thing) then you may be better off using
+C<Scalar::Util::refaddr()>, which is faster.
 
 =item overload::Overloaded(arg)
 
@@ -718,12 +737,12 @@ Returns C<undef> or a reference to the method that implements C<op>.
 
 =head1 Overloading constants
 
-For some application Perl parser mangles constants too much.  It is possible
-to hook into this process via overload::constant() and overload::remove_constant()
-functions.
+For some applications, the Perl parser mangles constants too much.
+It is possible to hook into this process via C<overload::constant()>
+and C<overload::remove_constant()> functions.
 
 These functions take a hash as an argument.  The recognized keys of this hash
-are
+are:
 
 =over 8
 
@@ -779,9 +798,6 @@ From these methods they may be called as
          overload::constant integer => sub {Math::BigInt->new(shift)};
        }
 
-B<BUGS> Currently overloaded-ness of constants does not propagate
-into C<eval '...'>.
-
 =head1 IMPLEMENTATION
 
 What follows is subject to change RSN.