diff --git a/.github/workflows/compile.yml b/.github/workflows/compile.yml
index 1b62c43..cbe1efe 100644
--- a/.github/workflows/compile.yml
+++ b/.github/workflows/compile.yml
@@ -4,15 +4,40 @@ on: [push, pull_request]
 
 jobs:
   test:
-    name: Compile
+    name: Compile (${{ matrix.sys }})
     runs-on: windows-latest
+    strategy:
+      matrix:
+        include:
+          - { sys: mingw64, env: x86_64 }
+          - { sys: mingw32, env: i686 }
+          - { sys: ucrt64,  env: ucrt-x86_64 }
+          - { sys: clang64, env: clang-x86_64 }
+    defaults:
+      run:
+        shell: msys2 {0}
     steps:
       - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
       - uses: msys2/setup-msys2@v2
         with:
           update: true
-          msystem: mingw64
-          install: mingw-w64-x86_64-llvm
+          cache: true
+          msystem: ${{ matrix.sys }}
+          install: >-
+            mingw-w64-${{ matrix.env }}-toolchain
+            mingw-w64-${{ matrix.env }}-clang
+            mingw-w64-${{ matrix.env }}-make
+            make
+
+      - name: Add environment variables
+        run: |
+          echo "export PATH=/${{ matrix.sys }}/bin:$PATH" >> $GITHUB_ENV
+          echo "export CC=clang" >> $GITHUB_ENV
+          echo "export CXX=clang++" >> $GITHUB_ENV
+
       - name: Compile source code
         run: |
           echo "::group::Clang++ version"
@@ -21,3 +46,13 @@ jobs:
           echo "::group::Compiling"
           make
           echo "::endgroup::"
+
+      - name: Export artifacts
+        uses: actions/upload-artifact@v2
+        with:
+          name: build-artifacts-${{ matrix.env }}
+          path: |
+            ./transf_server.exe
+            ./transf_client.exe
+          if-no-files-found: warn
+          retention-days: 30
diff --git a/include/network.h b/include/network.h
index 9f6f6ba..91cbbaf 100644
--- a/include/network.h
+++ b/include/network.h
@@ -12,6 +12,7 @@
 #include <string>
 #include <thread>
 #include <vector>
+#include <functional>
 
 typedef uint8_t ip_version;
 typedef int ip_family;
@@ -176,7 +177,7 @@ class BasicSocket {
 class SocketPeer : public BasicSocket {
    protected:
     BasicSocket* m_p_bsock_from;
-    mutable std::list<const PeerCloseHandler> m_pCloseHandlers;
+    mutable std::list<PeerCloseHandler> m_pCloseHandlers;
 
    public:
     SocketPeer() = default;
@@ -241,9 +242,9 @@ class SocketClient : public BasicSocket {
 class SocketServer : public BasicSocket {
    protected:
     std::map<u_long, SocketPeer&> m_clients;  // TODO: unused
-    mutable std::list<const StreamHandler> m_pStreamHandlers;
-    mutable std::list<const MessageHandler> m_pMessageHandlers;
-    mutable std::list<const ServerCloseHandler> m_pCloseHandlers;
+    mutable std::list<StreamHandler> m_pStreamHandlers;
+    mutable std::list<MessageHandler> m_pMessageHandlers;
+    mutable std::list<ServerCloseHandler> m_pCloseHandlers;
     int m_max_clients = SOMAXCONN;
     mutable bool m_serving = false;
     mutable std::vector<std::thread> m_threads;
diff --git a/src/ansi.tpp b/src/ansi.tpp
index d3668d3..d19567b 100644
--- a/src/ansi.tpp
+++ b/src/ansi.tpp
@@ -26,6 +26,7 @@
 //===----------------------------------------------------------------------===//
 */
 
+#include <algorithm>
 #include <ostream>
 #include <sstream>
 
diff --git a/transf_client.cpp b/transf_client.cpp
index cf6f4fc..c3cca11 100644
--- a/transf_client.cpp
+++ b/transf_client.cpp
@@ -114,13 +114,13 @@ int send_file(SocketClient& remote, const std::string& fp, char* buf, int buf_si
                          rate, "%)", ansi::reset);
         }
 
-        auto print_fail = [&fp, &ANSI_PREV_LINE, &IS_DEBUG]() {
+        auto print_fail = [&fp, &IS_DEBUG]() {
             logger.print(IS_DEBUG ? ""
                                   : ansi::clear_line + ansi::cursor_prev_line(1) +
                                         ansi::cursor_pos_x(fp.size() + 6),
                          ansi::rgb_fg(139, 0, 0), "  (Failed)", ansi::reset);
         };
-        auto print_success = [&fp, &ANSI_PREV_LINE, &IS_DEBUG]() {
+        auto print_success = [&fp, &IS_DEBUG]() {
             logger.print(IS_DEBUG
                              ? ""
                              : ansi::clear_line + ansi::cursor_prev_line(1) + ansi::clear_line +