+ xo-alloc + xo-object + xo-alloc docs + GC utests

xo-object/include/xo/object/String.hpp

@@ -0,0 +1,54 @@
+/* @file String.hpp
+ *
+ * author: Roland Conybeare, Aug 2025
+ */
+
+#include "xo/alloc/IAlloc.hpp"
+#include "xo/alloc/Object.hpp"
+
+namespace xo {
+    namespace obj {
+        class String : public Object {
+        public:
+            enum Owner { unique, shared };
+
+            /** donwcase from @p x iff x is actually a String. Otherwise nullptr **/
+            static gp<String> from(gp<Object> x);
+
+            /** create copy of string @p s, using allocator @ref Object::mm **/
+            static gp<String> copy(const char * s);
+            /** create copy of string @p s, using allocator @p mm **/
+            static gp<String> copy(gc::IAlloc * mm, const char * s);
+
+            /** create empty string with @p z bytes of string space **/
+            static gp<String> allocate(std::size_t z);
+            /** create string containing contents of @p s1 follwed by contents of @p s2 **/
+            static gp<String> append(gp<String> s1, gp<String> s2);
+
+            const char * c_str() const { return chars_; }
+            std::size_t length() const;
+
+            // inherited from Object..
+
+            virtual std::size_t _shallow_size() const override;
+            virtual Object * _shallow_copy() const override;
+            virtual std::size_t _forward_children() override;
+
+        private:
+            String(Owner owner, std::size_t z, char * s);
+            /** create instance, copying string contents (when @p copy_flag is true) using allocator @p mm **/
+            String(gc::IAlloc * mm, Owner owner, std::size_t z, char * s, bool copy);
+
+        private:
+            /** true iff storage in @ref chars_ is owned by this String.
+             **/
+            Owner owner_ = Owner::shared;
+            /** length of @ref chars_ in bytes (storage allocated, not necessarily string length) **/
+            std::size_t z_chars_ = 0;
+            /** string contents.  always null-terminated **/
+            char * chars_ = nullptr;
+        };
+    } /*namespace obj*/
+} /*namespace xo*/
+
+/* end String.hpp */