Enabled cppcheck for code analysis

.github/workflows/cppcheck.yml

@@ -0,0 +1,23 @@
+name: cppcheck
+
+on:
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  cppcheck:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - uses: linuxdeepin/action-cppcheck@main
+      with:
+        github_token: ${{ secrets.GITHUB_TOKEN }}
+        repository: ${{ github.repository }}
+        pull_request_id: ${{ github.event.pull_request.number }}
+        allow_approve: false
+        enable_qtcheck: false
+
+    - run: cat report.xml

test/test_case/basic.ipp

@@ -18,11 +18,14 @@
 template <typename T> bool operator<(T lhs, wrap<T> rhs) { return lhs < rhs.value; }
 template <typename T> bool operator<(wrap<T> lhs, T rhs) { return lhs.value < rhs; }
 
+void unused() { }
+
 TEST_CASE("construction", "[construction]")
 {
     SECTION("default construction")
     {
         FLAT_CONTAINER<int, int> fm;
+        int unused;
     }
 
     SECTION("iter construction")