From 3349cea2898c9c6f2ab13b5c18b2fcfcb2351120 Mon Sep 17 00:00:00 2001
From: Roland Conybeare <rconybeare@gmail.com>
Date: Thu, 15 Jan 2026 10:46:38 -0500
Subject: [PATCH] xo-object2: + StringOps + utest

---
 xo-object2/include/xo/object2/StringOps.hpp | 36 ++++++++++++++
 xo-object2/utest/CMakeLists.txt             |  1 +
 xo-object2/utest/DString.test.cpp           |  2 +-
 xo-object2/utest/StringOps.test.cpp         | 54 +++++++++++++++++++++
 4 files changed, 92 insertions(+), 1 deletion(-)
 create mode 100644 xo-object2/include/xo/object2/StringOps.hpp
 create mode 100644 xo-object2/utest/StringOps.test.cpp

diff --git a/xo-object2/include/xo/object2/StringOps.hpp b/xo-object2/include/xo/object2/StringOps.hpp
new file mode 100644
index 00000000..3cc71988
--- /dev/null
+++ b/xo-object2/include/xo/object2/StringOps.hpp
@@ -0,0 +1,36 @@
+/** @file StringOps.hpp
+*
+ *  @author Roland Conybeare, Jan 2026
+ **/
+
+#pragma once
+
+#include "string/IGCObject_DString.hpp"
+#include "DString.hpp"
+
+namespace xo {
+    namespace scm {
+        /** @brief string functions
+         *
+         *  note: separate from DString
+         **/
+        struct StringOps {
+            using AGCObject = xo::mm::AGCObject;
+            using AAllocator = xo::mm::AAllocator;
+            using size_type = DString::size_type;
+
+            template <typename AFacet = AGCObject>
+            static obj<AFacet,DString> empty(obj<AAllocator> mm,
+                                             size_type cap);
+        };
+
+        template <typename AFacet>
+        obj<AFacet,DString>
+        StringOps::empty(obj<AAllocator> mm, size_type cap)
+        {
+            return obj<AFacet,DString>(DString::empty(mm, cap));
+        }
+    }
+}
+
+/* end StringOps.hpp */
diff --git a/xo-object2/utest/CMakeLists.txt b/xo-object2/utest/CMakeLists.txt
index a681e52c..7207b7db 100644
--- a/xo-object2/utest/CMakeLists.txt
+++ b/xo-object2/utest/CMakeLists.txt
@@ -4,6 +4,7 @@ set(UTEST_EXE utest.object2)
 set(UTEST_SRCS
     object2_utest_main.cpp
     DString.test.cpp
+    StringOps.test.cpp
     X1Collector.test.cpp
     Printable.test.cpp
 )
diff --git a/xo-object2/utest/DString.test.cpp b/xo-object2/utest/DString.test.cpp
index 213f5023..226d63c8 100644
--- a/xo-object2/utest/DString.test.cpp
+++ b/xo-object2/utest/DString.test.cpp
@@ -3,7 +3,7 @@
  *  @author Roland Conybeare, Jan 2026
  **/
 
-#include <xo/object2/DString.hpp>
+#include <xo/object2/StringOps.hpp>
 #include <xo/alloc2/arena/IAllocator_DArena.hpp>
 #include <catch2/catch.hpp>
 #include <cctype>
diff --git a/xo-object2/utest/StringOps.test.cpp b/xo-object2/utest/StringOps.test.cpp
new file mode 100644
index 00000000..60069b53
--- /dev/null
+++ b/xo-object2/utest/StringOps.test.cpp
@@ -0,0 +1,54 @@
+/** @file StringOps.test.cpp
+ *
+ *  @author Roland Conybeare, Jan 2026
+ **/
+
+#include <xo/object2/StringOps.hpp>
+#include <xo/alloc2/arena/IAllocator_DArena.hpp>
+#include <catch2/catch.hpp>
+#include <cstring>
+
+namespace xo {
+    using xo::scm::StringOps;
+    using xo::scm::DString;
+    using xo::mm::AAllocator;
+    using xo::mm::AGCObject;
+    using xo::mm::DArena;
+    using xo::mm::ArenaConfig;
+    using xo::facet::with_facet;
+    using xo::facet::obj;
+
+    namespace ut {
+        TEST_CASE("StringOps-empty", "[object2][StringOps]")
+        {
+            ArenaConfig cfg { .name_ = "testarena",
+                              .size_ = 4*1024 };
+            DArena arena = DArena::map(cfg);
+            auto alloc = with_facet<AAllocator>::mkobj(&arena);
+
+            obj<AGCObject, DString> s = StringOps::empty(alloc, 16);
+
+            REQUIRE(s.data() != nullptr);
+            REQUIRE(s.data()->capacity() == 16);
+            REQUIRE(s.data()->size() == 0);
+            REQUIRE(s.data()->chars()[0] == '\0');
+        }
+
+        TEST_CASE("StringOps-empty-with-content", "[object2][StringOps]")
+        {
+            ArenaConfig cfg { .name_ = "testarena",
+                              .size_ = 4*1024 };
+            DArena arena = DArena::map(cfg);
+            auto alloc = with_facet<AAllocator>::mkobj(&arena);
+
+            obj<AGCObject, DString> s = StringOps::empty(alloc, 32);
+
+            s.data()->sprintf("hello %s %d", "world", 42);
+
+            REQUIRE(s.data()->size() == 14);
+            REQUIRE(std::strcmp(s.data()->chars(), "hello world 42") == 0);
+        }
+    } /*namespace ut*/
+} /*namespace xo*/
+
+/* end StringOps.test.cpp */