diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 91346af..a3d5aa9 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -5,11 +5,13 @@ jobs:
     steps:
       - checkout: self
         submodules: true
-      - script:
-          docker run -v${PWD}:/build
-            arbmind/qbs-clang7:1
-            build --file /build/BasiC++17.qbs --build-directory /tmp/build
-            -p autotest-runner
+      - task: ShellScript@2
+        inputs:
+          scriptPath: thirdparty/git_clone_googletest.sh
+      - script: docker run -v${PWD}:/build
+          arbmind/qbs-clang7:1
+          build --file /build/BasiC++17.qbs --build-directory /tmp/build
+          -p autotest-runner
 
   - job: Windows
     pool:
@@ -21,6 +23,9 @@ jobs:
       - script: qbs config --list profiles
       - checkout: self
         submodules: true
+      - task: ShellScript@2
+        inputs:
+          scriptPath: thirdparty/git_clone_googletest.sh
       - script: qbs
-            build profile:MSVC2019-x64 --file BasiC++17.qbs --build-directory %TMP%\build
-            -p autotest-runner
+          build profile:MSVC2019-x64 --file BasiC++17.qbs --build-directory %TMP%\build
+          -p autotest-runner
diff --git a/src/meta17.lib/meta17/IndexPack.iterate.h b/src/meta17.lib/meta17/IndexPack.iterate.h
new file mode 100644
index 0000000..b1a14ff
--- /dev/null
+++ b/src/meta17.lib/meta17/IndexPack.iterate.h
@@ -0,0 +1,13 @@
+#pragma once
+#include "Index.h"
+#include "IndexPack.h"
+
+namespace meta17 {
+
+/// "constexpr for": Iterate over a sequence with compile-time available indices
+template<class Callable, size_t... Is>
+constexpr auto forEachIndex(IndexPack<Is...>, Callable&& callable) {
+    return (..., callable(_index<Is>));
+}
+
+} // namespace meta17
diff --git a/src/meta17.lib/meta17/IndexPack.iterate.test.cpp b/src/meta17.lib/meta17/IndexPack.iterate.test.cpp
new file mode 100644
index 0000000..7f18a63
--- /dev/null
+++ b/src/meta17.lib/meta17/IndexPack.iterate.test.cpp
@@ -0,0 +1,11 @@
+#include "IndexPack.iterate.h"
+
+#include "Index.wrap.h" // UnwrapType
+#include <cinttypes>
+
+using namespace meta17;
+
+static_assert(forEachIndex(index_pack<12, 23>, [s = 0](auto i) mutable {
+                  s += to_value<decltype(i)>;
+                  return s;
+              }) == 35);
diff --git a/src/meta17.lib/meta17/meta17.qbs b/src/meta17.lib/meta17/meta17.qbs
index 68193d9..c9d8221 100644
--- a/src/meta17.lib/meta17/meta17.qbs
+++ b/src/meta17.lib/meta17/meta17.qbs
@@ -50,6 +50,7 @@ Product {
             "IndexPack.extract.h",
             "IndexPack.for.h",
             "IndexPack.h",
+            "IndexPack.iterate.h",
             "IndexPack.make.h",
             "IndexPack.ops.h",
             "IndexPack.trait.h",
@@ -152,6 +153,7 @@ Product {
         "Unreachable.h",
         "align.h",
         "same.h",
+        "ptr.h",
     ]
 
     Export {
diff --git a/src/meta17.lib/meta17/meta17.tests.qbs b/src/meta17.lib/meta17/meta17.tests.qbs
index 3b198f8..c0da832 100644
--- a/src/meta17.lib/meta17/meta17.tests.qbs
+++ b/src/meta17.lib/meta17/meta17.tests.qbs
@@ -53,6 +53,7 @@ Application {
         files: [
             "IndexPack.extract.test.cpp",
             "IndexPack.for.test.cpp",
+            "IndexPack.iterate.test.cpp",
             "IndexPack.make.test.cpp",
             "IndexPack.ops.test.cpp",
             "IndexPack.test.cpp",
@@ -150,5 +151,6 @@ Application {
         "StaticErrorExpr.test.cpp",
         "align.test.cpp",
         "main.cpp",
+        "ptr.test.cpp",
     ]
 }
diff --git a/src/meta17.lib/meta17/ptr.h b/src/meta17.lib/meta17/ptr.h
new file mode 100644
index 0000000..fd42184
--- /dev/null
+++ b/src/meta17.lib/meta17/ptr.h
@@ -0,0 +1,8 @@
+#pragma once
+
+namespace meta17 {
+
+template<class T>
+constexpr T* nullptr_to = nullptr;
+
+}
diff --git a/src/meta17.lib/meta17/ptr.test.cpp b/src/meta17.lib/meta17/ptr.test.cpp
new file mode 100644
index 0000000..0a6dfb8
--- /dev/null
+++ b/src/meta17.lib/meta17/ptr.test.cpp
@@ -0,0 +1,7 @@
+#include "ptr.h"
+#include "same.h"
+
+using namespace meta17;
+
+static_assert(same<decltype(nullptr_to<int>), int* const>);
+static_assert(nullptr_to<int> == nullptr);
diff --git a/src/strong17.lib/strong17/Strong.opaque.h b/src/strong17.lib/strong17/Strong.opaque.h
index 5156e44..e80f7de 100644
--- a/src/strong17.lib/strong17/Strong.opaque.h
+++ b/src/strong17.lib/strong17/Strong.opaque.h
@@ -4,8 +4,6 @@
 #include "Strong.make.h"
 
 #include "meta17/Type.h"
-#include "meta17/TypePack.h"
-#include "meta17/TypePack.recurse.h"
 
 #define STRONG_OPAQUE(NAME, TYPE, ...)                                                                                 \
     struct NAME;                                                                                                       \
diff --git a/src/strong17.lib/strong17/Strong.opaque.test.cpp b/src/strong17.lib/strong17/Strong.opaque.test.cpp
new file mode 100644
index 0000000..a45549e
--- /dev/null
+++ b/src/strong17.lib/strong17/Strong.opaque.test.cpp
@@ -0,0 +1,19 @@
+#include "Strong.opaque.h"
+
+#include <gtest/gtest.h>
+
+namespace testing {
+
+STRONG_OPAQUE(HelloTest, int, struct HelloTag);
+
+} // namespace testing
+
+STRONG_OPAQUE(HelloGlobal, int, struct HelloTag);
+
+TEST(Strong, opaque) {
+    constexpr auto ht = testing::HelloTest{15};
+    static_assert(ht.v == 15);
+
+    constexpr auto hg = HelloGlobal{23};
+    static_assert(hg.v == 23);
+}
diff --git a/src/strong17.lib/strong17/Strong.trait.h b/src/strong17.lib/strong17/Strong.trait.h
index 26bfe1a..e297591 100644
--- a/src/strong17.lib/strong17/Strong.trait.h
+++ b/src/strong17.lib/strong17/Strong.trait.h
@@ -12,14 +12,11 @@ using meta17::False;
 using meta17::is_type_template;
 using meta17::same;
 
-template<class, class = void>
-struct IsStrong : False {};
-
-template<class T>
-struct IsStrong<T, std::void_t<Base<T>>> : Bool<is_type_template<Base<T>, Strong>> {};
+template<class T, class = void>
+constexpr auto is_strong = false;
 
 template<class T>
-constexpr auto is_strong = IsStrong<std::remove_const_t<T>>{};
+constexpr auto is_strong<T, std::void_t<Base<T>>> = is_type_template<Base<T>, Strong>;
 
 template<class, class = void>
 struct IsOpaque : False {};
diff --git a/src/strong17.lib/strong17/Strong.weaken.h b/src/strong17.lib/strong17/Strong.weaken.h
index 2e64f45..64f44c7 100644
--- a/src/strong17.lib/strong17/Strong.weaken.h
+++ b/src/strong17.lib/strong17/Strong.weaken.h
@@ -18,11 +18,11 @@ using meta17::UnwrapType;
 
 /// like extractValue, but does nothing for non-strong types
 template<class S>
-constexpr auto weakenType(Type<S> = {}) -> std::enable_if_t<is_strong<S>.v, Type<ExtractValue<Base<S>>>> {
+constexpr auto weakenType(Type<S> = {}) -> std::enable_if_t<is_strong<S>, Type<ExtractValue<Base<S>>>> {
     return {};
 }
 template<class T>
-constexpr auto weakenType(Type<T> = {}) -> std::enable_if_t<!is_strong<T>.v, Type<T>> {
+constexpr auto weakenType(Type<T> = {}) -> std::enable_if_t<!is_strong<T>, Type<T>> {
     return {};
 }
 template<class S>
diff --git a/src/strong17.lib/strong17/strong17.tests.qbs b/src/strong17.lib/strong17/strong17.tests.qbs
index 181c003..688cd11 100644
--- a/src/strong17.lib/strong17/strong17.tests.qbs
+++ b/src/strong17.lib/strong17/strong17.tests.qbs
@@ -16,6 +16,7 @@ Application {
         "Strong.inspect.test.cpp",
         "Strong.make.test.cpp",
         "Strong.manip.test.cpp",
+        "Strong.opaque.test.cpp",
         "Strong.ops.test.cpp",
         "Strong.ostream.cpp",
         "Strong.test.cpp",