## PR — **Silence minor C++ warnings (tests + Region)**

**Summary**

- Remove three `-Wunused` warnings:
  1. `m` set but not used in `region_pulse_and_binding_tests.cpp`
  2. `t` unused in `region_tick_tests.cpp`
  3. `dstAny` unused in `Region.cpp`
- No functional changes; strictly warning cleanup.

------

### 1) `src/cpp/tests/region_pulse_and_binding_tests.cpp` — mark `m` as used

```diff
@@
-    RegionMetrics m = region.tick("x", 0.5);
+    RegionMetrics m = region.tick("x", 0.5);
+    // Silence -Wunused-but-set-variable in this smoke test.
+    (void)m;
```

------

### 2) `src/cpp/tests/region_tick_tests.cpp` — drop unused `t` (or mark used)

**Option A (simplest; preferred):**

```diff
@@
-    Tract& t = region.connectLayers(src, dst, 1.0, false);
-    (void)t; // keep if you want the declaration; else remove this line
+    // We only need the side effect (subscriptions); ignore the return ref.
+    (void)region.connectLayers(src, dst, 1.0, false);
```

**Option B (keep the variable but mark it used):**

```diff
@@
-    Tract& t = region.connectLayers(src, dst, 1.0, false);
+    Tract& t = region.connectLayers(src, dst, 1.0, false);
     // Silence -Wunused-variable; the subscription side-effect is what we test.
     (void)t;
```

Pick one (A or B).

------

### 3) `src/cpp/Region.cpp` — remove unused `dstAny`

```diff
@@ int Region::connectLayersWindowed(int sourceIndex, int destIndex,
-    auto* dstAny = layers[destIndex].get();
+    // (no local 'dstAny' needed; branches use 'dstNeurons' or OutputLayer2D directly)
```

(Just delete the `dstAny` declaration line if it still exists.)

------

### Why this fixes the warnings

- Casting to `(void)` counts as a use in C++, so the compiler stops complaining without changing behavior.
- Removing `dstAny` avoids the `-Wunused-variable` message in `Region.cpp`.

------

### Optional (nice to have, not required)

If you want a reusable helper for future tests:

```cpp
// In a small test utils header:
template <class T>
inline void GN_UNUSED(const T&) noexcept {}
```

Then use `GN_UNUSED(m);` or `GN_UNUSED(t);` instead of `(void)`. But the patches above already keep the tree warning‑free.

------

**That’s it.** After applying, rebuild—those three warnings should disappear while keeping all functionality intact.