diff --git a/default.nix b/default.nix
index 19d55283..3aff84df 100644
--- a/default.nix
+++ b/default.nix
@@ -328,6 +328,7 @@ let
   # xo general-purpose devutils
   devutils = [
     pkgs.nix-tree  # note: needs GHC
+    #pkgs.nix
 
     pkgs.git
     pkgs.gh    # github cli
@@ -335,6 +336,7 @@ let
     pkgs.bloaty
 
     pkgs.catch2
+    pkgs.cli11
 
     pkgs.btop
   ]
diff --git a/pkgs/xo-alloc2.nix b/pkgs/xo-alloc2.nix
index 0ca4afee..74d86500 100644
--- a/pkgs/xo-alloc2.nix
+++ b/pkgs/xo-alloc2.nix
@@ -1,7 +1,7 @@
 {
   # nixpkgs dependencies
   lib, stdenv, cmake, catch2,
-  doxygen,
+  doxygen, cli11,
 
   python3Packages,
 
@@ -44,6 +44,7 @@ stdenv.mkDerivation (finalattrs:
     nativeBuildInputs = [
       cmake
       catch2
+      cli11
       xo-randomgen
       xo-cmake
     ] ++ lib.optionals buildDocs [
diff --git a/xo-alloc2/utest/CMakeLists.txt b/xo-alloc2/utest/CMakeLists.txt
index a19d1f47..2dec2979 100644
--- a/xo-alloc2/utest/CMakeLists.txt
+++ b/xo-alloc2/utest/CMakeLists.txt
@@ -4,12 +4,11 @@
 set(UTEST_EXE utest.alloc2)
 set(UTEST_SRCS
     alloc2_utest_main.cpp
+    TestUtil.cpp
     objectmodel.test.cpp
     arena.test.cpp
     IAllocator_Any.test.cpp
     DArenaIterator.test.cpp
-#    Collector.test.cpp
-#    DX1CollectorIterator.test.cpp
     Generation.test.cpp
     Role.test.cpp
     VisitReason.test.cpp
diff --git a/xo-alloc2/utest/DArenaIterator.test.cpp b/xo-alloc2/utest/DArenaIterator.test.cpp
index 2c7503c5..a3e95d96 100644
--- a/xo-alloc2/utest/DArenaIterator.test.cpp
+++ b/xo-alloc2/utest/DArenaIterator.test.cpp
@@ -3,10 +3,11 @@
  *  @author Roland Conybeare, Dec 2025
  **/
 
-#include "Allocator.hpp"
-#include "AllocIterator.hpp"
-#include "Arena.hpp"
-//#include "arena/IAllocator_DArena.hpp"
+#include "TestUtil.hpp"
+#include <xo/alloc2/Allocator.hpp>
+#include <xo/alloc2/AllocIterator.hpp>
+#include <xo/alloc2/Arena.hpp>
+#include <xo/alloc2/ArenaIterator.hpp>
 #include "arena/IAllocIterator_DArenaIterator.hpp"
 #include "padding.hpp"
 #include <xo/indentlog/scope.hpp>
@@ -39,6 +40,8 @@ namespace xo {
     namespace ut {
         TEST_CASE("IAllocIterator_Xfer_DArenaIterator", "[alloc2]")
         {
+            auto log = Utest::ut_scope();
+
             /* verify IAllocIterator_Xfer is constructible + satisfies concept checks */
             IAllocIterator_Xfer<DArenaIterator, IAllocIterator_DArenaIterator> xfer;
             REQUIRE(IAllocIterator_Xfer<DArenaIterator, IAllocIterator_DArenaIterator>::_valid);
@@ -46,6 +49,8 @@ namespace xo {
 
         TEST_CASE("IAllocIterator_Any", "[alloc2]")
         {
+            auto log = Utest::ut_scope();
+
             /* verify IAllocIterator_Any is constructible + satisfies concept checks */
             IAllocIterator_Any any;
             REQUIRE(IAllocIterator_Any::_valid);
@@ -53,6 +58,8 @@ namespace xo {
 
         TEST_CASE("obj_IAllocIterator", "[alloc2]")
         {
+            auto log = Utest::ut_scope();
+
             /* verify variant obj constructible */
             obj<AAllocIterator> obj_any;
             REQUIRE(obj_any.iface());
@@ -61,6 +68,8 @@ namespace xo {
 
         TEST_CASE("IAllocIterator-disabled-1", "[alloc2]")
         {
+            auto log = Utest::ut_scope();
+
             /* verify iteration over empty arena */
             /* typed allocator a1o */
             ArenaConfig cfg { .name_       = "testarena",
@@ -97,6 +106,8 @@ namespace xo {
 
         TEST_CASE("IAllocIterator-emptyarena", "[alloc2]")
         {
+            auto log = Utest::ut_scope();
+
             /* verify iteration over empty arena */
             /* typed allocator a1o */
             ArenaConfig cfg { .name_              = "testarena",
@@ -153,7 +164,7 @@ namespace xo {
 
         TEST_CASE("IAllocIterator-singlearena", "[alloc2]")
         {
-            scope log(XO_DEBUG(false));
+            auto log = Utest::ut_scope();
 
             ArenaConfig cfg { .name_              = "testarena",
                               .size_              = 64*1024,
diff --git a/xo-alloc2/utest/Generation.test.cpp b/xo-alloc2/utest/Generation.test.cpp
index e62359ea..6507e19b 100644
--- a/xo-alloc2/utest/Generation.test.cpp
+++ b/xo-alloc2/utest/Generation.test.cpp
@@ -3,6 +3,7 @@
  *  @author Roland Conybeare, May 2026
  **/
 
+#include "TestUtil.hpp"
 #include "Generation.hpp"
 #include <catch2/catch.hpp>
 
@@ -14,6 +15,8 @@ namespace xo {
 
         TEST_CASE("Generation-1", "[Generation]")
         {
+            auto log = Utest::ut_scope();
+
             REQUIRE(Generation::nursery() == 0);
             REQUIRE(Generation::g0() == 0);
             REQUIRE(Generation::g1() == 1);
diff --git a/xo-alloc2/utest/IAllocator_Any.test.cpp b/xo-alloc2/utest/IAllocator_Any.test.cpp
index 5d23c6ed..68d510ef 100644
--- a/xo-alloc2/utest/IAllocator_Any.test.cpp
+++ b/xo-alloc2/utest/IAllocator_Any.test.cpp
@@ -3,6 +3,7 @@
  *  @author Roland Conybeare, May 2026
  **/
 
+#include "TestUtil.hpp"
 #include <xo/alloc2/Allocator.hpp>
 #include <catch2/catch.hpp>
 #include <sys/wait.h>
@@ -16,6 +17,8 @@ namespace xo {
 
         TEST_CASE("IAllocator_Any", "[alloc2][death]")
         {
+            auto log = Utest::ut_scope();
+
             // null allocator
             obj<AAllocator> alloc_any;
 
diff --git a/xo-alloc2/utest/ResourceVisitor.test.cpp b/xo-alloc2/utest/ResourceVisitor.test.cpp
index 0869d387..49c0f553 100644
--- a/xo-alloc2/utest/ResourceVisitor.test.cpp
+++ b/xo-alloc2/utest/ResourceVisitor.test.cpp
@@ -3,6 +3,7 @@
  *  @author Roland Conybeare, May 2026
  **/
 
+#include "TestUtil.hpp"
 #include <xo/alloc2/ResourceVisitor.hpp>
 #include <catch2/catch.hpp>
 
@@ -13,6 +14,8 @@ namespace xo {
 
         TEST_CASE("ResourceVisitor-1", "[resourcevisitor]")
         {
+            auto log = Utest::ut_scope();
+
             obj<AResourceVisitor> v;
 
             REQUIRE(v.iface());
diff --git a/xo-alloc2/utest/Role.test.cpp b/xo-alloc2/utest/Role.test.cpp
index d1de6fe4..a4c38d29 100644
--- a/xo-alloc2/utest/Role.test.cpp
+++ b/xo-alloc2/utest/Role.test.cpp
@@ -3,6 +3,7 @@
  *  @author Roland Conybeare, May 2026
  **/
 
+#include "TestUtil.hpp"
 #include "role.hpp"
 #include <catch2/catch.hpp>
 
@@ -13,6 +14,8 @@ namespace xo {
 
         TEST_CASE("Role-1", "[Role]")
         {
+            auto log = Utest::ut_scope();
+
             /* 1. there are two distinct valid roles, 'to' and 'from',
              * 2. valid roles fall in interval [begin, end)
              */
diff --git a/xo-alloc2/utest/TestUtil.cpp b/xo-alloc2/utest/TestUtil.cpp
new file mode 100644
index 00000000..c52a5d79
--- /dev/null
+++ b/xo-alloc2/utest/TestUtil.cpp
@@ -0,0 +1,24 @@
+/** @file TestUtil.cpp
+ *
+ *  @author Roland Conybeare, May 2026
+ **/
+
+#include "TestUtil.hpp"
+#include <catch2/catch.hpp>
+
+namespace xo {
+    UtestConfig *
+    UtestConfig::instance() {
+        static UtestConfig s_instance;
+
+        return &s_instance;
+    };
+
+    scope
+    Utest::ut_scope() {
+        return scope(XO_DEBUG(UtestConfig::instance()->debug_flag()),
+                     xtag("name", Catch::getResultCapture().getCurrentTestName()));
+    }
+}
+
+/* end TestUtil.cpp */
diff --git a/xo-alloc2/utest/TestUtil.hpp b/xo-alloc2/utest/TestUtil.hpp
new file mode 100644
index 00000000..20253bb6
--- /dev/null
+++ b/xo-alloc2/utest/TestUtil.hpp
@@ -0,0 +1,44 @@
+/** @file TestUtil.hpp
+ *
+ *  @author Roland Conybeare, May 2026
+ **/
+
+#pragma once
+
+#include <xo/indentlog/scope.hpp>
+
+namespace xo {
+
+    /** unit-test configuration here
+     *
+     *  TODO: promote to its own library, along with UtestListener
+     **/
+    struct UtestConfig {
+        bool debug_flag() const { return debug_flag_; }
+
+        /** announce each test using catch2's listener api **/
+        bool announce_flag_ = false;
+        /** enable debug output for all (!) tests **/
+        bool debug_flag_ = false;
+
+        static UtestConfig * instance();
+    };
+
+    /** RAII logging for catch unit tests
+     *
+     *  Use:
+     *    TEST_CASE(name, tags, ..)
+     *    {
+     *       scope log = Utest::ut_scope();
+     *
+     *       ...
+     *       log && log(xtag("foo", ...));
+     *    }
+     **/
+    struct Utest {
+        static scope ut_scope();
+    };
+
+} /*namespace xo*/
+
+/* end TestUtil.hpp */
diff --git a/xo-alloc2/utest/VisitReason.test.cpp b/xo-alloc2/utest/VisitReason.test.cpp
index 44bfcc38..6fccac80 100644
--- a/xo-alloc2/utest/VisitReason.test.cpp
+++ b/xo-alloc2/utest/VisitReason.test.cpp
@@ -3,6 +3,7 @@
  *  @author Roland Conybeare, May 2026
  **/
 
+#include "TestUtil.hpp"
 #include <xo/alloc2/VisitReason.hpp>
 #include <catch2/catch.hpp>
 
@@ -13,6 +14,8 @@ namespace xo {
 
         TEST_CASE("VisitReason-1", "[visitreason]")
         {
+            auto log = Utest::ut_scope();
+
             REQUIRE(VisitReason::unspecified() == VisitReason::unspecified());
 
             REQUIRE(VisitReason::unspecified() != VisitReason::forward());
diff --git a/xo-alloc2/utest/alloc2_utest_main.cpp b/xo-alloc2/utest/alloc2_utest_main.cpp
index 02d64a23..d907b0d9 100644
--- a/xo-alloc2/utest/alloc2_utest_main.cpp
+++ b/xo-alloc2/utest/alloc2_utest_main.cpp
@@ -1,6 +1,100 @@
 /* file alloc2_utest_main.cpp */
 
-#define CATCH_CONFIG_MAIN
-#include "catch2/catch.hpp"
+#include "TestUtil.hpp"
+#include <xo/subsys/Subsystem.hpp>
+#include <xo/indentlog/scope.hpp>
+#include <CLI/CLI.hpp>
+
+#define CATCH_CONFIG_RUNNER
+#include <catch2/catch.hpp>
+
+namespace xo {
+
+    struct UtestListener : Catch::TestEventListenerBase {
+        using TestEventListenerBase::TestEventListenerBase;
+
+        // TestCasweInfo members: .name, .className, .description, .tags, lineInfo {.file, .line}
+        virtual void testCaseStarting(const Catch::TestCaseInfo & info) override {
+            using std::cerr;
+            using std::endl;
+
+            // preamble
+
+            if (UtestConfig::instance()->announce_flag_) {
+                cerr << "Starting unit test: "
+                << "[" << info.name << "]"
+                << " at "
+                << "[" << info.lineInfo.file << ":" << info.lineInfo.line << "]"
+                << endl;
+            }
+        }
+
+        virtual void testCaseEnded(const Catch::TestCaseStats & stats) override {
+            // postamble
+        }
+
+        // also sectionStarting / sectionEnded
+
+    };
+
+    CATCH_REGISTER_LISTENER(UtestListener);
+}
+
+int
+main(int argc, char* argv[])
+{
+    using xo::UtestConfig;
+    using xo::scope;
+    using xo::xtag;
+
+    using std::cout;
+    using std::cerr;
+    using std::endl;
+
+    //cerr << xtag("cli11", CLI11_VERSION) << endl; // version 2.5.0
+
+    CLI::App app{"utest.alloc2: xo-alloc2 unit tests"};
+    app.set_help_flag(); // disable default help impl, see below
+    {
+        app.add_flag("--debug",
+                     UtestConfig::instance()->debug_flag_,
+                     "enable debug logging (for all tests)");
+        app.add_flag("--announce",
+                     UtestConfig::instance()->announce_flag_,
+                     "announce each test via UtestListener");
+    }
+    bool help_flag = false;
+    {
+        app.add_flag("--help,-h,-?", help_flag, "print this help message and exit");
+    }
+
+    app.allow_extras();
+    CLI11_PARSE(app, argc, argv);
+
+    std::vector<const char *> argv2 = {argv[0]};
+
+    if (help_flag) {
+        // actual help impl, falls through to Session below
+
+        cout << "utest.alloc2 options" << endl;
+        cout << app.help() << endl;
+        cout << "catch2 options" << endl;
+
+        argv2.push_back("--help");
+    } else {
+        // keep program name
+        for (auto & x : app.remaining())
+            argv2.push_back(x.c_str());
+
+        using xo::Subsystem;
+        Subsystem::initialize_all();
+
+    }
+
+    scope log(XO_DEBUG(UtestConfig::instance()->debug_flag()), "start catch2 session");
+
+    // run catch2's test session / help
+    return Catch::Session().run(argv2.size(), argv2.data());
+}
 
 /* end alloc2_utest_main.cpp */
diff --git a/xo-alloc2/utest/arena.test.cpp b/xo-alloc2/utest/arena.test.cpp
index 95077f6b..4f88ffd2 100644
--- a/xo-alloc2/utest/arena.test.cpp
+++ b/xo-alloc2/utest/arena.test.cpp
@@ -3,6 +3,7 @@
  *  @author Roland Conybeare, Dec 2025
  **/
 
+#include "TestUtil.hpp"
 #include <xo/alloc2/Allocator.hpp>
 #include <xo/alloc2/Arena.hpp>
 #include <xo/arena/print.hpp>
@@ -33,6 +34,8 @@ namespace xo {
     namespace ut {
         TEST_CASE("IAllocator_Xfer_DArena", "[alloc2]")
         {
+            auto log = Utest::ut_scope();
+
             IAllocator_Xfer<DArena, IAllocator_DArena> xfer;
 
             REQUIRE(IAllocator_Xfer<DArena, IAllocator_DArena>::_valid);
@@ -40,6 +43,8 @@ namespace xo {
 
         TEST_CASE("DArena-medium", "[alloc2][DArena]")
         {
+            auto log = Utest::ut_scope();
+
             ArenaConfig cfg { .name_ = "testarena",
                               .size_ = 10*1024*1024 };
             DArena arena = DArena::map(cfg);
@@ -83,6 +88,8 @@ namespace xo {
 
         TEST_CASE("allocator-any-1", "[alloc2][AAllocator]")
         {
+            auto log = Utest::ut_scope();
+
             /* empty allocator alloc1 */
             obj<AAllocator> alloc1;
 
@@ -122,6 +129,8 @@ namespace xo {
 
         TEST_CASE("allocator-expand-1", "[alloc2][AAllocator]")
         {
+            auto log = Utest::ut_scope();
+
             /* typed allocator a1o */
             ArenaConfig cfg { .name_ = "testarena",
                               .size_ = 1,
@@ -160,6 +169,8 @@ namespace xo {
 
         TEST_CASE("allocator-alloc-1", "[alloc2][AAllocator]")
         {
+            auto log = Utest::ut_scope();
+
             /* typed allocator a1o */
             ArenaConfig cfg { .name_ = "testarena",
                               .size_ = 64*1024,
@@ -207,6 +218,8 @@ namespace xo {
 
         TEST_CASE("allocator-alloc-2", "[alloc2][Allocator]")
         {
+            auto log = Utest::ut_scope();
+
             using header_type = AllocHeader;
 
             /* typed allocator a1o, with object header */
@@ -293,6 +306,8 @@ namespace xo {
 
         TEST_CASE("allocator-alloc-3", "[alloc2][Allocator]")
         {
+            auto log = Utest::ut_scope();
+
             using header_type = AllocHeader;
 
             /* typed allocator a1o, with object header + guard bytes */
@@ -363,6 +378,8 @@ namespace xo {
 
         TEST_CASE("allocator-fail-1", "[alloc2][AAllocator]")
         {
+            auto log = Utest::ut_scope();
+
             /* typed allocator a1o */
             ArenaConfig cfg { .name_ = "testarena",
                               .size_ = 64*1024,
diff --git a/xo-alloc2/utest/dp.test.cpp b/xo-alloc2/utest/dp.test.cpp
index e507b730..c2c91d70 100644
--- a/xo-alloc2/utest/dp.test.cpp
+++ b/xo-alloc2/utest/dp.test.cpp
@@ -3,6 +3,7 @@
  *  @author Roland Conybeare, May 2026
  **/
 
+#include "TestUtil.hpp"
 #include "dp.hpp"
 #include <xo/alloc2/Allocator.hpp>
 #include <xo/alloc2/Arena.hpp>
@@ -33,6 +34,8 @@ namespace xo {
 
         TEST_CASE("dp-1", "[dp]")
         {
+            auto log = Utest::ut_scope();
+
             //ArenaConfig cfg { .name_ = "testarena", .size_ = 1024 };
             //DArena arena = DArena::map(cfg);
             //auto mm = obj<AAllocator,DArena>(&arena);
@@ -55,6 +58,8 @@ namespace xo {
 
         TEST_CASE("dp-2", "[dp]")
         {
+            auto log = Utest::ut_scope();
+
             uint32_t counter = 0;
             Foo foo(&counter);
 
@@ -77,6 +82,8 @@ namespace xo {
 
         TEST_CASE("dp-DArena", "[dp][DArena]")
         {
+            auto log = Utest::ut_scope();
+
             ArenaConfig cfg { .name_ = "testarena", .size_ = 1024 };
             DArena arena = DArena::map(cfg);
             //auto mm = obj<AAllocator,DArena>(&arena);
diff --git a/xo-alloc2/utest/objectmodel.test.cpp b/xo-alloc2/utest/objectmodel.test.cpp
index 1fcc9a81..5f08b2c8 100644
--- a/xo-alloc2/utest/objectmodel.test.cpp
+++ b/xo-alloc2/utest/objectmodel.test.cpp
@@ -79,6 +79,7 @@
  *  Application code will deal with ubox<AComplex,DPolarCoords>
  **/
 
+#include "TestUtil.hpp"
 #include <catch2/catch.hpp>
 #include <cmath>
 #include <cassert>
@@ -576,6 +577,8 @@ namespace xo {
 
         TEST_CASE("objectmodel-specific-1", "[objectmodel]")
         {
+            auto log = Utest::ut_scope();
+
             /* arg=0, mag=1 -> 1+0i */
             DPolarCoords polar{0.0, 1.0};
             IComplex_Specific<DPolarCoords> polar_iface;
@@ -588,6 +591,8 @@ namespace xo {
 
         TEST_CASE("objectmodel-specific-2", "[objectmodel]")
         {
+            auto log = Utest::ut_scope();
+
             /* arg=0, mag=1 -> 1+0i */
             DRectCoords rect{1.0, 0.0};
             IComplex_Specific<DRectCoords> rect_iface;
@@ -600,6 +605,8 @@ namespace xo {
 
         TEST_CASE("uniquebox-1", "[objectmodel]")
         {
+            auto log = Utest::ut_scope();
+
             auto tmp = std::make_unique<DPolarCoords>(0.0, 1.0);
             OUniqueBox<AComplex, DPolarCoords> box{tmp.release()};
 
@@ -611,6 +618,8 @@ namespace xo {
 
         TEST_CASE("router-1", "[objectmodel]")
         {
+            auto log = Utest::ut_scope();
+
             using Object = OUniqueBox<AComplex, DPolarCoords>;
             auto tmp = std::make_unique<DPolarCoords>(0.0, 1.0);
 
@@ -624,6 +633,8 @@ namespace xo {
 
         TEST_CASE("routing-type-1", "[objectmodel]")
         {
+            auto log = Utest::ut_scope();
+
             using Object = OUniqueBox<AComplex, DPolarCoords>;
             auto tmp = std::make_unique<DPolarCoords>(0.0, 1.0);
 
@@ -637,6 +648,8 @@ namespace xo {
 
         TEST_CASE("ubox-1", "[objectmodel]")
         {
+            auto log = Utest::ut_scope();
+
             auto tmp = std::make_unique<DPolarCoords>(0.0, 1.0);
             ubox<AComplex,DPolarCoords> box{tmp.release()};
 
@@ -648,6 +661,8 @@ namespace xo {
 
         TEST_CASE("ubox-2", "[objectmodel]")
         {
+            auto log = Utest::ut_scope();
+
             auto tmp = std::make_unique<DRectCoords>(1.0, 0.0);
             ubox<AComplex,DRectCoords> box{tmp.release()};
 
@@ -659,12 +674,16 @@ namespace xo {
 
         TEST_CASE("ubox-any-1", "[objectmodel]")
         {
+            auto log = Utest::ut_scope();
+
             /* default ctor */
             ubox<AComplex> any;
         }
 
         TEST_CASE("ubox-any-2", "[objectmodel]")
         {
+            auto log = Utest::ut_scope();
+
             /* equivalent to ubox<AComplex,DRectCoords>, but impl doesn't use std::unique_ptr */
             ubox<AComplex,DRectCoords> any{new DRectCoords{1.0, 0.0}};
 
@@ -676,6 +695,8 @@ namespace xo {
 
         TEST_CASE("ubox-any-3", "[objectmodel]")
         {
+            auto log = Utest::ut_scope();
+
             /* equivalent to ubox<AComplex,DRectCoords>, but impl doesn't use std::unique_ptr */
             ubox<AComplex,DRectCoords> z1{new DRectCoords{1.0, 0.0}};
 
diff --git a/xo-arena/src/arena/DArena.cpp b/xo-arena/src/arena/DArena.cpp
index fb60031a..0c429558 100644
--- a/xo-arena/src/arena/DArena.cpp
+++ b/xo-arena/src/arena/DArena.cpp
@@ -538,9 +538,9 @@ namespace xo {
             if (lo_ + target_z > hi_) [[unlikely]] {
                 this->capture_error(error::reserve_exhausted, src_fn, target_z);
 
-                fprintf(stderr, "DArena::expand: reserve exhausted");
-                print_backtrace_dwarf(true /*demangle_flag*/);
-                std::terminate();
+                //fprintf(stderr, "DArena::expand: reserve exhausted");
+                //print_backtrace_dwarf(true /*demangle_flag*/);
+                //std::terminate();
 
                 return false;
             }
diff --git a/xo-indentlog/include/xo/indentlog/scope.hpp b/xo-indentlog/include/xo/indentlog/scope.hpp
index 42a664c9..8ed57497 100644
--- a/xo-indentlog/include/xo/indentlog/scope.hpp
+++ b/xo-indentlog/include/xo/indentlog/scope.hpp
@@ -125,6 +125,20 @@ namespace xo {
     public:
         template <typename... Tn>
         basic_scope(scope_setup setup, Tn&&... rest);
+        basic_scope(basic_scope && other) noexcept
+            : dest_sbuf_{other.dest_sbuf_},
+              style_{other.style_},
+              name1_{other.name1_},
+              name2_{other.name2_},
+              file_{other.file_},
+              line_{other.line_},
+              finalized_{other.finalized_}
+        {
+            other.finalized_ = true;
+        }
+        basic_scope(const basic_scope &) = delete;
+        basic_scope & operator=(const basic_scope &) = delete;
+        basic_scope & operator=(basic_scope &&) = delete;
         ~basic_scope();
 
         bool enabled() const { return !finalized_; }