Fix various points raised after code reviews

Some fixes, a great slam and then some

1 files changed, 47 insertions, 0 deletions

diff --git a/examples/cppx/default.cpp b/examples/cppx/default.cpp
new file mode 100644
index 000000000..503cffe41
--- /dev/null
+++ b/examples/cppx/default.cpp
@@ -0,0 +1,47 @@
+//====================================================================
+// Library code: implementing the metaclass (once)
+
+$class basic_value {
+    basic_value() = default;
+    basic_value(const basic_value& that) = default;
+    basic_value(basic_value&& that) = default;
+    basic_value& operator=(const basic_value& that) = default;
+    basic_value& operator=(basic_value&& that) = default;
+
+    constexpr {
+        for... (auto f : $basic_value.variables())
+            if (!f.has_access()) f.make_private();
+        for... (auto f : $basic_value.functions()) {
+            if (!f.has_access()) f.make_public();
+            compiler.require(!f.is_protected(), "a value type may not have a protected function");
+            compiler.require(!f.is_virtual(),   "a value type may not have a virtual function");
+            compiler.require(!f.is_destructor() || f.is_public(), "a value destructor must be public");
+        }
+    }
+};
+
+$class value : basic_value { };
+
+
+//====================================================================
+// User code: using the metaclass to write a type (many times)
+
+value Point {
+    int x = 0, y = 0;
+    Point(int xx, int yy) : x{xx}, y{yy} { }
+};
+
+Point get_some_point() { return {1,1}; }
+
+int main() {
+
+    Point p1(50,100), p2;
+    p2 = get_some_point();
+    p2.x = 42;
+
+}
+
+// Compiler Explorer note: Click the "triangle ! icon" to see the output:
+constexpr {
+    compiler.debug($Point);
+}