Improved error message when accessing @private from other modules. Added convenience functions to Maybe.

lib/std/collections/maybe.c3

@@ -1,16 +1,43 @@
 module std::collections::maybe(<Type>);
+import std::io;
 
-struct Maybe
+struct Maybe (Printable)
 {
 	Type value;
 	bool has_value;
 }
 
+fn usz! Maybe.to_format(&self, Formatter* f) @dynamic
+{
+	if (self.has_value) return f.printf("[%s]", self.value);
+	return f.printf("[EMPTY]");
+}
+
+fn void Maybe.set(&self, Type val)
+{
+	*self = { .value = val, .has_value = true };
+}
+
+fn void Maybe.reset(&self)
+{
+	*self = {};
+}
+
 fn Maybe value(Type val)
 {
 	return { .value = val, .has_value = true };
 }
 
+fn Maybe Maybe.with_value(Type val) @operator(construct)
+{
+	return { .value = val, .has_value = true };
+}
+
+fn Maybe Maybe.empty() @operator(construct)
+{
+	return { };
+}
+
 const Maybe EMPTY = { };
 
 macro Type! Maybe.get(self)