Add $base to exp proto, and make a version of Complex.exp which takes…

… the $base argument.

src/core/Complex.pm

@@ -33,6 +33,10 @@ class Complex does Numeric is Cool {
         Complex.new($.re.Num.exp * $.im.Num.cos, $.re.Num.exp * $.im.Num.sin);
     }
 
+    multi method exp(Complex $exponent: Numeric $base) {
+        $base ** $exponent;
+    }
+
     multi method sin($base = Radians) {
         $.re.sin($base) * $.im.cosh($base) + ($.re.cos($base) * $.im.sinh($base))i;
     }

src/core/Cool-num.pm

@@ -168,7 +168,7 @@ augment class Cool {
 proto sub abs($x) { $x.abs }
 multi sub prefix:<abs>($x) { $x.abs }
 proto sub sign($x) { $x.sign }
-proto sub exp($exponent) { $exponent.exp }
+proto sub exp($exponent, $base = e) { $exponent.exp($base) }
 proto sub log($x, $base = e) { $x.log($base) }
 proto sub log10($x) { $x.log10 }
 proto sub cis($angle) { $angle.cis; }