add indication that an option takes a value to the help message

The help message didn't specify that an option took a value.

Here's before and after for the option specification in t/11-usage.t

Usage: 11-usage.t [-rv] [long options] [arguments]
	--bare
	--define                 (default: arch=i386, isize=4)
	--input                  (default: test.txt)
	--libs                   (default: one, two)
	-r                       recursive
	--test                   run in test mode
	-v, --verbose            turn on verbose output (default: 2)

Usage: 11-usage.t [-rv] [long options] [arguments]
	--bare <value>
	--define key=<value>     (default: arch=i386, isize=4)
	--input <value>          (default: test.txt)
	--libs <value>           (default: one, two)
	-r                       recursive
	--test                   run in test mode
	-v [<value>], --verbose [<value>] turn on verbose output (default: 2)

lib/Getopt/Lucid.pm

@@ -385,7 +385,7 @@ sub usage {
     for my $opt ( sort { $a->{strip} cmp $b->{strip} } values %{$self->{spec}} ) {
         my $names = [ @{ $opt->{names} } ];
         push @doc, [
-            _build_usage_left_column( $names, \@short_opts ),
+            _build_usage_left_column( $names, \@short_opts, $opt->{type} ),
             _build_usage_right_column( $opt->{doc}, $opt->{default}, $opt->{type} ),
         ];
     }
@@ -400,7 +400,7 @@ sub usage {
 }
 
 sub _build_usage_left_column {
-    my ($names, $all_short_opts) = @_;
+    my ($names, $all_short_opts, $type) = @_;
     my @sorted_names =
       sort { length $a <=> length $b } map { my $s = $_; $s =~ s/^-*//; $s } @$names;
 
@@ -409,13 +409,20 @@ sub _build_usage_left_column {
 
     push @$all_short_opts, @short_opts;
 
+    my $value =
+          $type eq 'keypair' ? ' key=<value>'
+        : $type eq 'counter' ? ' [<value>]'
+        : $type ne 'switch'  ? ' <value>'
+        :                      ''
+        ;
+
     my $group = sub {
         my $list = shift;
         '-' . ( @$list == 1 ? $list->[0] : '[' . join( '|', @$list ) . ']' );
     };
     my $prepare = sub {
         my $list = shift;
-        return ( length $list->[0] > 1 ? '-' : '' ) . $group->($list) if @$list;
+        return ( length $list->[0] > 1 ? '-' : '' ) . $group->($list) . $value if @$list;
         return;
     };
 

t/11-usage.t

@@ -28,13 +28,13 @@ my $spec = [
 
 my @expectations = (
     qr/^Usage: \Q$prog\E \[-rv] \[long options] \[arguments]$/,
-    qr/^\s+--bare\s*$/,
-    qr/^\s+--define\s+\(default: arch=i386, isize=4\)$/,
-    qr/^\s+--input\s+\(default: test\.txt\)$/,
-    qr/^\s+--libs\s+\(default: one, two\)$/,
+    qr/^\s+--bare <value>\s*$/,
+    qr/^\s+--define key=<value>\s+\(default: arch=i386, isize=4\)$/,
+    qr/^\s+--input <value>\s+\(default: test\.txt\)$/,
+    qr/^\s+--libs <value> \s+\(default: one, two\)$/,
     qr/^\s+-r\s+recursive$/,
     qr/^\s+--test\s+run in test mode$/,
-    qr/^\s+-v, --verbose\s+turn on verbose output \(default: 2\)$/,
+    qr/^\s+-v \[<value>\], --verbose \[<value>\]\s+turn on verbose output \(default: 2\)$/,
 );
 
 plan tests => 2 + @expectations;