Suppress ‘useless’ warning in overload.pm

[perl5.git] / lib / overload.pm

diff --git a/lib/overload.pm b/lib/overload.pm
index 1b89043..4892a31 100644 (file)
--- a/lib/overload.pm
+++ b/lib/overload.pm
@@ -1,12 +1,38 @@
 package overload;
 
-our $VERSION = '1.16';
+our $VERSION = '1.18';
+
+%ops = (
+    with_assign         => "+ - * / % ** << >> x .",
+    assign              => "+= -= *= /= %= **= <<= >>= x= .=",
+    num_comparison      => "< <= >  >= == !=",
+    '3way_comparison'   => "<=> cmp",
+    str_comparison      => "lt le gt ge eq ne",
+    binary              => '& &= | |= ^ ^=',
+    unary               => "neg ! ~",
+    mutators            => '++ --',
+    func                => "atan2 cos sin exp abs log sqrt int",
+    conversion          => 'bool "" 0+ qr',
+    iterators           => '<>',
+    filetest            => "-X",
+    dereferencing       => '${} @{} %{} &{} *{}',
+    matching            => '~~',
+    special             => 'nomethod fallback =',
+);
+
+my %ops_seen;
+for $category (keys %ops) {
+    $ops_seen{$_}++ for (split /\s+/, $ops{$category});
+}
 
 sub nil {}
 
 sub OVERLOAD {
   $package = shift;
   my %arg = @_;
+  for (keys %arg) {
+    warn "overload arg '$_' is invalid" unless $ops_seen{$_};
+  }
   my ($sub, $fb);
   $ {$package . "::OVERLOAD"}{dummy}++; # Register with magic by touching.
   $fb = ${$package . "::()"}; # preserve old fallback value RT#68196
@@ -50,7 +76,7 @@ sub unimport {
 sub Overloaded {
   my $package = shift;
   $package = ref $package if ref $package;
-  $package->can('()');
+  mycan ($package, '()');
 }
 
 sub ov_method {
@@ -128,22 +154,6 @@ sub mycan {                                # Real can would leave stubs.
              'qr'        => 0x10000, # HINT_NEW_RE
             );
 
-%ops = ( with_assign     => "+ - * / % ** << >> x .",
-        assign           => "+= -= *= /= %= **= <<= >>= x= .=",
-        num_comparison   => "< <= >  >= == !=",
-        '3way_comparison'=> "<=> cmp",
-        str_comparison   => "lt le gt ge eq ne",
-        binary           => '& &= | |= ^ ^=',
-        unary            => "neg ! ~",
-        mutators         => '++ --',
-        func             => "atan2 cos sin exp abs log sqrt int",
-        conversion       => 'bool "" 0+ qr',
-        iterators        => '<>',
-         filetest         => "-X",
-        dereferencing    => '${} @{} %{} &{} *{}',
-        matching         => '~~',
-        special          => 'nomethod fallback =');
-
 use warnings::register;
 sub constant {
   # Arguments: what, sub
@@ -379,6 +389,9 @@ Most of the overloadable operators map one-to-one to these keys.
 Exceptions, including additional overloadable operations not
 apparent from this hash, are included in the notes which follow.
 
+A warning is issued if an attempt is made to register an operator not found
+above.
+
 =over 5
 
 =item * C<not>