tests/infra: move to c++23 (std pins, g++-14 in CI, deducing this in tests)

Cameron Custer · Cameron Custer · commit d4f43270a69b · 2026-07-06T22:18:09.000-07:00
diff --git a/.github/actions/setup/action.yml b/.github/actions/setup/action.yml
@@ -9,7 +9,9 @@ runs:
         chmod +x llvm.sh
         sudo ./llvm.sh 22
         sudo apt-get update
-        sudo apt-get install -y clang-format-22 clang-tidy-22
+        sudo apt-get install -y clang-format-22 clang-tidy-22 g++-14
+        sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-14 100
         clang-22 --version
         clang-format-22 --version
         clang-tidy-22 --version
+        g++ --version
diff --git a/.github/workflows/programming_team_code_ci.yml b/.github/workflows/programming_team_code_ci.yml
@@ -12,6 +12,12 @@ jobs:
     - uses: actions/checkout@v1
     - name: Set up Python
       uses: actions/setup-python@v1
+    - name: Install g++-14
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y g++-14
+        sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-14 100
+        g++ --version
     - name: Install dependencies
       run: |
         pip install "setuptools<81"
@@ -53,6 +59,12 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
+    - name: Install g++-14
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y g++-14
+        sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-14 100
+        g++ --version
     - name: g++ with gcc
       run: make --directory=tests/ compile_gcc
 
diff --git a/.verify-helper/config.toml b/.verify-helper/config.toml
@@ -2,7 +2,7 @@
 CXX = "g++"
 CXXFLAGS = [
 	"-O2",
-	"-std=c++20",
+	"-std=c++23",
 	"-fsanitize=address,undefined",
 	"-fno-sanitize-recover=all",
 	"-fstack-protector",
diff --git a/tests/.config/.clang-format b/tests/.config/.clang-format
@@ -88,5 +88,5 @@ SpacesInCStyleCastParentheses: false
 SpacesInContainerLiterals: false
 SpacesInParentheses: false
 SpacesInSquareBrackets: false
-Standard: c++20
+Standard: Latest
 ...
diff --git a/tests/.config/.gcc_compile_flags b/tests/.config/.gcc_compile_flags
@@ -10,4 +10,4 @@
 -Wduplicated-cond
 -Werror
 -O2
--std=c++20
+-std=c++23
diff --git a/tests/Makefile b/tests/Makefile
@@ -1,9 +1,9 @@
 help:
 	@echo "command                              | explanation"
 	@echo "------------------------------------ | -----------"
-	@echo "make compile_gcc                     | compile all tests with -std=c++20 for warnings"
+	@echo "make compile_gcc                     | compile all tests with -std=c++23 for warnings"
 	@echo "                                     |"
-	@echo "make compile_clang                   | compile all tests with clang, -std=c++20 for warnings"
+	@echo "make compile_clang                   | compile all tests with clang, -std=c++23 for warnings"
 	@echo "                                     |"
 	@echo "make grep_clangformat_cppcheck       | various greps to catch certain things, clang-format, cppcheck"
 	@echo "                                     |"
diff --git a/tests/library_checker_aizu_tests/cd_asserts.hpp b/tests/library_checker_aizu_tests/cd_asserts.hpp
@@ -5,16 +5,16 @@ void cd_asserts(vector<vi> adj) {
   vi naive_par_decomp(sz(adj), -1);
   vi par = cd(adj, [&](int cent) -> void {
     assert(decomp_size[cent] == -1);
-    auto dfs = [&](auto&& self, int u, int p) -> int {
+    auto dfs = [&](this auto&& self, int u, int p) -> int {
       if (p != -1) naive_par_decomp[u] = cent;
       int sub_size = 1;
       for (int v : adj[u])
-        if (v != p) sub_size += self(self, v, u);
+        if (v != p) sub_size += self(v, u);
       return sub_size;
     };
-    decomp_size[cent] = dfs(dfs, cent, -1);
+    decomp_size[cent] = dfs(cent, -1);
     for (int u : adj[cent]) {
-      int sz_subtree = dfs(dfs, u, cent);
+      int sz_subtree = dfs(u, cent);
       assert(1 <= sz_subtree &&
              2 * sz_subtree <= decomp_size[cent]);
     }
diff --git a/tests/library_checker_aizu_tests/data_structures/permutation_tree.test.cpp b/tests/library_checker_aizu_tests/data_structures/permutation_tree.test.cpp
@@ -15,16 +15,16 @@ int main() {
   cout << sz(ch) << '\n';
   int curr_time = 0;
   vi node_to_time(sz(ch), -1);
-  auto dfs = [&](auto&& self, int u, int p) -> void {
+  auto dfs = [&](this auto&& self, int u, int p) -> void {
     node_to_time[u] = curr_time++;
     cout << (p == -1 ? p : node_to_time[p]) << " "
          << pt.p[u].mn_idx << " "
          << pt.p[u].mn_idx + pt.p[u].len - 1 << " "
          << (pt.p[u].is_join || empty(ch[u]) ? "linear"
                                              : "prime")
          << '\n';
-    for (int v : ch[u]) self(self, v, u);
+    for (int v : ch[u]) self(v, u);
   };
-  dfs(dfs, root, -1);
+  dfs(root, -1);
   return 0;
 }
diff --git a/tests/library_checker_aizu_tests/dsu/kruskal_tree_aizu.test.cpp b/tests/library_checker_aizu_tests/dsu/kruskal_tree_aizu.test.cpp
@@ -30,14 +30,14 @@ int main() {
   rep(i, n, kt.id) mst_sum += weight[i];
   vi depth(2 * n);
   vi actual_par(2 * n, -1);
-  auto dfs = [&](auto&& self, int v) -> void {
+  auto dfs = [&](this auto&& self, int v) -> void {
     for (int u : kt.g[v]) {
       depth[u] = 1 + depth[v];
       actual_par[u] = v;
-      self(self, u);
+      self(u);
     }
   };
-  dfs(dfs, kt.id - 1);
+  dfs(kt.id - 1);
   rep(i, 0, n) rep(j, i + 1, n) {
     int u = i, v = j;
     while (u != v)
diff --git a/tests/library_checker_aizu_tests/edge_cd_asserts.hpp b/tests/library_checker_aizu_tests/edge_cd_asserts.hpp
@@ -1,19 +1,19 @@
 #pragma once
 auto edge_cd_asserts = [&](int cent, int split) -> void {
   assert(0 < split && split < sz(adj[cent]));
-  auto dfs = [&](auto&& self, int u, int p) -> int {
+  auto dfs = [&](this auto&& self, int u, int p) -> int {
     int siz = 1;
     for (int v : adj[u])
-      if (v != p) siz += self(self, v, u);
+      if (v != p) siz += self(v, u);
     return siz;
   };
-  int sz_all = dfs(dfs, cent, -1);
+  int sz_all = dfs(cent, -1);
   assert(sz_all >= 3);
   array<int, 2> cnts = {0, 0};
   array<int, 2> max_cnt = {0, 0};
   array<int, 2> number_of_cnts = {0, 0};
   rep(i, 0, sz(adj[cent])) {
-    int sz_subtree = dfs(dfs, adj[cent][i], cent);
+    int sz_subtree = dfs(adj[cent][i], cent);
     assert(2 * sz_subtree <= sz_all);
     cnts[i < split] += sz_subtree;
     max_cnt[i < split] =
diff --git a/tests/library_checker_aizu_tests/graphs/dijkstra_lib_checker.test.cpp b/tests/library_checker_aizu_tests/graphs/dijkstra_lib_checker.test.cpp
@@ -26,21 +26,21 @@ int main() {
   vector<bool> vis(n);
   vis[t] = 1;
   vector<array<int, 2>> path;
-  auto dfs = [&](auto&& self, int u) -> bool {
+  auto dfs = [&](this auto&& self, int u) -> bool {
     if (u == s) return 1;
     for (auto [v, w] : adj_inv[u]) {
       if (!vis[v] && len[v] != LLONG_MAX &&
           len[v] + w == len[u]) {
         vis[v] = 1;
-        if (self(self, v)) {
+        if (self(v)) {
           path.push_back({v, u});
           return 1;
         }
       }
     }
     return 0;
   };
-  assert(dfs(dfs, t));
+  assert(dfs(t));
   cout << len[t] << " " << sz(path) << '\n';
   for (auto [u, v] : path) cout << u << " " << v << '\n';
   return 0;
diff --git a/tests/library_checker_aizu_tests/handmade_tests/count_paths.test.cpp b/tests/library_checker_aizu_tests/handmade_tests/count_paths.test.cpp
@@ -19,20 +19,20 @@ vector<ll> count_paths_per_node(vector<vi> adj, int k) {
   vector<ll> num_paths(sz(adj));
   cd(adj, [&](int cent) {
     vector pre_d{1}, cur_d{0};
-    auto dfs = [&](auto&& self, int u, int p,
+    auto dfs = [&](this auto&& self, int u, int p,
                  int d) -> ll {
       if (d > k) return 0LL;
       if (sz(cur_d) <= d) cur_d.push_back(0);
       cur_d[d]++;
       ll cnt = 0;
       if (k - d < sz(pre_d)) cnt += pre_d[k - d];
       for (int c : adj[u])
-        if (c != p) cnt += self(self, c, u, d + 1);
+        if (c != p) cnt += self(c, u, d + 1);
       num_paths[u] += cnt;
       return cnt;
     };
     auto dfs_child = [&](int child) -> ll {
-      ll cnt = dfs(dfs, child, cent, 1);
+      ll cnt = dfs(child, cent, 1);
       pre_d.resize(sz(cur_d));
       for (int i = 1; i < sz(cur_d) && cur_d[i]; i++)
         pre_d[i] += cur_d[i], cur_d[i] = 0;
@@ -72,15 +72,15 @@ vector<ll> count_paths_per_length(vector<vi> adj) {
   if (sz(adj) >= 2) num_paths[1] = sz(adj) - 1;
   edge_cd(adj, [&](int cent, int split) {
     vector<vector<double>> cnt(2, vector<double>(1));
-    auto dfs = [&](auto&& self, int u, int p, int d,
+    auto dfs = [&](this auto&& self, int u, int p, int d,
                  int side) -> void {
       if (sz(cnt[side]) == d) cnt[side].push_back(0.0);
       cnt[side][d]++;
       for (int c : adj[u])
-        if (c != p) self(self, c, u, 1 + d, side);
+        if (c != p) self(c, u, 1 + d, side);
     };
     rep(i, 0, sz(adj[cent]))
-      dfs(dfs, adj[cent][i], cent, 1, i < split);
+      dfs(adj[cent][i], cent, 1, i < split);
     vector<double> prod = conv(cnt[0], cnt[1]);
     rep(i, 0, sz(prod)) num_paths[i] += llround(prod[i]);
   });
diff --git a/tests/library_checker_aizu_tests/handmade_tests/dsu.test.cpp b/tests/library_checker_aizu_tests/handmade_tests/dsu.test.cpp
@@ -14,34 +14,34 @@ int main() {
       bool joined = dsu.join(u, v);
       {
         vector<bool> vis(n);
-        auto dfs = [&](auto&& self, int v) -> void {
+        auto dfs = [&](this auto&& self, int v) -> void {
           for (int u : adj[v]) {
             if (!vis[u]) {
               vis[u] = 1;
-              self(self, u);
+              self(u);
             }
           }
         };
         vis[u] = 1;
-        dfs(dfs, u);
+        dfs(u);
         assert(vis[v] != joined);
       }
       adj[u].push_back(v);
       adj[v].push_back(u);
       rep(i, 0, n) {
         vector<bool> vis(n);
         int cnt_nodes = 0;
-        auto dfs = [&](auto&& self, int v) -> void {
+        auto dfs = [&](this auto&& self, int v) -> void {
           cnt_nodes++;
           for (int u : adj[v]) {
             if (!vis[u]) {
               vis[u] = 1;
-              self(self, u);
+              self(u);
             }
           }
         };
         vis[i] = 1;
-        dfs(dfs, i);
+        dfs(i);
         assert(cnt_nodes == dsu.size(i));
       }
     }
diff --git a/tests/library_checker_aizu_tests/handmade_tests/functional_graph.test.cpp b/tests/library_checker_aizu_tests/handmade_tests/functional_graph.test.cpp
@@ -63,33 +63,33 @@ struct functional_graph_processor {
         }
         cycle.push_back(c);
       }
-      auto dfs = [&](auto self, int u2) -> void {
+      auto dfs = [&](this auto &&self, int u2) -> void {
         if (was2[u2] == attempt) return;
         was2[u2] = attempt;
         int v2 = nxt[u2];
-        self(self, v2);
+        self(v2);
         root_of[u2] = root_of[v2];
         depth[u2] = depth[v2] + 1;
         abr[v2].push_back(u2);
       };
-      dfs(dfs, u);
+      dfs(u);
     }
     for (auto u = 0; u < n; ++u)
       if (~cycle_pos[u]) cycle_prev[nxt[u]] = u;
     for (const auto &c : cycle) {
-      auto dfs = [&](auto self, int u) -> void {
+      auto dfs = [&](this auto &&self, int u) -> void {
         size[u] = 1;
         pos[u] = sz(order);
         order.push_back(u);
         for (auto v : abr[u]) {
-          self(self, v);
+          self(v);
           size[u] += size[v];
         }
         end[u] = sz(order);
       };
       int csize = 0;
       for (auto u : c) {
-        dfs(dfs, u);
+        dfs(u);
         csize += size[u];
       }
       for (auto u : c)
diff --git a/tests/library_checker_aizu_tests/handmade_tests/seg_tree_midpoint.test.cpp b/tests/library_checker_aizu_tests/handmade_tests/seg_tree_midpoint.test.cpp
@@ -6,7 +6,7 @@ int lg(int x) { return bit_width(x + 0u) - 1; }
 int main() {
   cin.tie(0)->sync_with_stdio(0);
   rep(n, 1, 5000) {
-    auto dfs = [&](auto&& self, int tl, int tr,
+    auto dfs = [&](this auto&& self, int tl, int tr,
                  int v) -> void {
       assert((v >= n) == ((tr - tl) == 1));
       if (v >= n) { // leaf node
@@ -58,11 +58,11 @@ int main() {
         assert(split(tl - 1234, tr - 1234) == tm - 1234);
         assert(split(tl - 1, tr - 1) == tm - 1);
         assert(split(tl + 50, tr + 50) == tm + 50);
-        self(self, tl, tm, 2 * v);
-        self(self, tm, tr, 2 * v + 1);
+        self(tl, tm, 2 * v);
+        self(tm, tr, 2 * v + 1);
       }
     };
-    dfs(dfs, 0, n, 1);
+    dfs(0, n, 1);
   }
   cout << "Hello World\n";
   return 0;
diff --git a/tests/library_checker_aizu_tests/trees/edge_cd_contour_range_query.test.cpp b/tests/library_checker_aizu_tests/trees/edge_cd_contour_range_query.test.cpp
@@ -14,12 +14,12 @@ struct sum_adj {
   //! stack for dfs is O(n)
   sum_adj(const vector<vi>& adj, const vector<ll>& sum):
     n(sz(sum)), sum(sum), sum_ch(n), p(n, -1) {
-    auto dfs = [&](auto&& self, int u) -> void {
+    auto dfs = [&](this auto&& self, int u) -> void {
       for (int c : adj[u])
         if (c != p[u])
-          p[c] = u, sum_ch[u] += sum[c], self(self, c);
+          p[c] = u, sum_ch[u] += sum[c], self(c);
     };
-    dfs(dfs, 0);
+    dfs(0);
   }
   //! @param u node
   //! @param delta number to add
@@ -50,17 +50,17 @@ struct contour_range_query {
     n(sz(a)), sum_a(adj, a), info(n) {
     edge_cd(adj, [&](int cent, int split) {
       vector<vector<ll>> sum_num(2, vector<ll>(1));
-      auto dfs = [&](auto&& self, int u, int p, int d,
+      auto dfs = [&](this auto&& self, int u, int p, int d,
                    int side) -> void {
         info[u].push_back({int(sz(bits)), d, side});
         if (sz(sum_num[side]) == d)
           sum_num[side].push_back(0);
         sum_num[side][d] += a[u];
         for (int c : adj[u])
-          if (c != p) self(self, c, u, 1 + d, side);
+          if (c != p) self(c, u, 1 + d, side);
       };
       rep(i, 0, sz(adj[cent]))
-        dfs(dfs, adj[cent][i], cent, 1, i < split);
+        dfs(adj[cent][i], cent, 1, i < split);
       bits.push_back({BIT(sum_num[0]), BIT(sum_num[1])});
     });
   }
diff --git a/tests/library_checker_aizu_tests/trees/edge_cd_contour_range_update.test.cpp b/tests/library_checker_aizu_tests/trees/edge_cd_contour_range_update.test.cpp
@@ -14,12 +14,12 @@ struct sum_adj {
   //! stack for dfs is O(n)
   sum_adj(const vector<vi>& adj, const vector<ll>& sum):
     n(sz(sum)), sum(sum), sum_ch(n), p(n, -1) {
-    auto dfs = [&](auto&& self, int u) -> void {
+    auto dfs = [&](this auto&& self, int u) -> void {
       for (int c : adj[u])
         if (c != p[u])
-          p[c] = u, sum_ch[u] += sum[c], self(self, c);
+          p[c] = u, sum_ch[u] += sum[c], self(c);
     };
-    dfs(dfs, 0);
+    dfs(0);
   }
   //! @param u node
   //! @param delta number to add
@@ -53,15 +53,15 @@ struct contour_range_update {
     n(sz(a)), a(a), sum_a(adj, vector<ll>(n)), info(n) {
     edge_cd(adj, [&](int cent, int split) {
       array<int, 2> mx_d = {0, 0};
-      auto dfs = [&](auto&& self, int u, int p, int d,
+      auto dfs = [&](this auto&& self, int u, int p, int d,
                    int side) -> void {
         mx_d[side] = max(mx_d[side], d);
         info[u].push_back({int(sz(bits)), d, side});
         for (int v : adj[u])
-          if (v != p) self(self, v, u, 1 + d, side);
+          if (v != p) self(v, u, 1 + d, side);
       };
       rep(i, 0, sz(adj[cent]))
-        dfs(dfs, adj[cent][i], cent, 1, i < split);
+        dfs(adj[cent][i], cent, 1, i < split);
       bits.push_back(
         {bit_rupq(mx_d[0] + 1), bit_rupq(mx_d[1] + 1)});
     });
diff --git a/tests/library_checker_aizu_tests/trees/edge_cd_count_paths_per_length.test.cpp b/tests/library_checker_aizu_tests/trees/edge_cd_count_paths_per_length.test.cpp
diff --git a/tests/library_checker_aizu_tests/trees/edge_cd_reroot_dp.test.cpp b/tests/library_checker_aizu_tests/trees/edge_cd_reroot_dp.test.cpp
diff --git a/tests/library_checker_aizu_tests/trees/shallowest_aizu_tree_height.test.cpp b/tests/library_checker_aizu_tests/trees/shallowest_aizu_tree_height.test.cpp
diff --git a/tests/library_checker_aizu_tests/trees/shallowest_lib_checker_tree_path_composite.test.cpp b/tests/library_checker_aizu_tests/trees/shallowest_lib_checker_tree_path_composite.test.cpp
diff --git a/tests/scripts/clangtidy.sh b/tests/scripts/clangtidy.sh
diff --git a/tests/scripts/compile_clang.sh b/tests/scripts/compile_clang.sh
diff --git a/tests/scripts/compile_commented_snippets.sh b/tests/scripts/compile_commented_snippets.sh
diff --git a/tests/scripts/grep_clangformat_cppcheck.sh b/tests/scripts/grep_clangformat_cppcheck.sh
