operator pre -- and decrement in Integer

t/base/features.t

@@ -324,6 +324,10 @@ function main [main] (args)
     test.is(vi1, 43, "var preincrement");
     i = ++vi1;
     test.is(i, 44, "var preincrement with assignment");
+    --vi1;
+    test.is(vi1, 43, "var peedecrement");
+    i = --vi1;
+    test.is(i, 42, "var predecrement with assignment");
 
     string s = "abc";
     test.is_string(s * 3, "abcabcabc", "repeat string");

winxedxx_classes.cxx

@@ -97,6 +97,11 @@ void WxxNull::increment()
     nullaccess("increment");
 }
 
+void WxxNull::decrement()
+{
+    nullaccess("decrement");
+}
+
 std::string WxxNull::get_string_keyed(int i)
 {
     nullaccess("get_pmc_keyed");
@@ -284,6 +289,11 @@ void WxxDefault::increment()
     notimplemented("increment");
 }
 
+void WxxDefault::decrement()
+{
+    notimplemented("decrement");
+}
+
 std::string WxxDefault::get_string_keyed(int i)
 {
     return get_pmc_keyed(i);
@@ -425,6 +435,11 @@ void WxxInteger::increment()
     ++i;
 }
 
+void WxxInteger::decrement()
+{
+    --i;
+}
+
 void WxxInteger::print() { std::cout << i; }
 
 //*************************************************************

winxedxx_default.h

@@ -30,6 +30,7 @@ class WxxDefault : public WxxObject
     WxxObject & set(const char *s);
     WxxObject & set(const std::string &s);
     void increment();
+    void decrement();
     std::string get_string_keyed(int i);
     WxxObjectPtr get_pmc_keyed(int i);
     WxxObjectPtr get_pmc_keyed(const std::string &s);

winxedxx_integer.h

@@ -32,6 +32,7 @@ class WxxInteger : public WxxDefault
     WxxObject & set(int value);
     WxxObject & set(double value);
     void increment();
+    void decrement();
     void print();
 private:
     int i;

winxedxx_null.h

@@ -25,6 +25,7 @@ class WxxNull : public WxxObject
     WxxObject & set(const char *s);
     WxxObject & set(const std::string &s);
     void increment();
+    void decrement();
     std::string get_string_keyed(int i);
     WxxObjectPtr get_pmc_keyed(int i);
     WxxObjectPtr get_pmc_keyed(const std::string &s);

winxedxx_object.h

@@ -24,6 +24,7 @@ class WxxObject
     virtual WxxObject & set(const char *s) = 0;
     virtual WxxObject & set(const std::string &s) = 0;
     virtual void increment() = 0;
+    virtual void decrement() = 0;
     virtual std::string get_string_keyed(int i) = 0;
     virtual WxxObjectPtr get_pmc_keyed(int i) = 0;
     virtual WxxObjectPtr get_pmc_keyed(const std::string &s) = 0;

winxedxx_objectptr.cxx

@@ -170,6 +170,12 @@ WxxObjectPtr & WxxObjectPtr::operator++()
     return *this;
 }
 
+WxxObjectPtr & WxxObjectPtr::operator--()
+{
+    object->decrement();
+    return *this;
+}
+
 int WxxObjectPtr::is_null() const
 {
     return object->is_null();

winxedxx_types.h

@@ -60,6 +60,7 @@ class WxxObjectPtr
     operator double() const;
     operator std::string() const;
     WxxObjectPtr & operator++();
+    WxxObjectPtr & operator--();
     int is_null() const;
     int instanceof(const std::string &type);
     std::string get_string() const;