Modernize standard library includes

This was automated with sed and git-clang-format, and then I had to
fix up the top of policy.cc by hand as git-clang-format accidentally
indented it by two spaces.

75 files changed, 180 insertions, 184 deletions

diff --git a/apt-pkg/acquire-item.cc b/apt-pkg/acquire-item.cc
index 400838dcb..3c491adc0 100644
--- a/apt-pkg/acquire-item.cc
+++ b/apt-pkg/acquire-item.cc
@@ -32,8 +32,13 @@
 #include <apt-pkg/tagfile.h>
 
 #include <algorithm>
-#include <ctime>
+#include <cerrno>
 #include <chrono>
+#include <cstddef>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <ctime>
 #include <iostream>
 #include <memory>
 #include <numeric>
@@ -42,11 +47,6 @@
 #include <string>
 #include <unordered_set>
 #include <vector>
-#include <errno.h>
-#include <stddef.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
 #include <sys/stat.h>
 #include <unistd.h>
 
diff --git a/apt-pkg/acquire-method.cc b/apt-pkg/acquire-method.cc
index 089582561..7b1f4f1b5 100644
--- a/apt-pkg/acquire-method.cc
+++ b/apt-pkg/acquire-method.cc
@@ -24,15 +24,15 @@
 #include <apt-pkg/strutl.h>
 
 #include <algorithm>
+#include <cstdarg>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
 #include <iostream>
 #include <iterator>
 #include <sstream>
 #include <string>
 #include <vector>
-#include <stdarg.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
 #include <unistd.h>
 									/*}}}*/
 
diff --git a/apt-pkg/acquire-method.h b/apt-pkg/acquire-method.h
index b4b238c4c..edee93996 100644
--- a/apt-pkg/acquire-method.h
+++ b/apt-pkg/acquire-method.h
@@ -22,8 +22,8 @@
 #include <apt-pkg/hashes.h>
 #include <apt-pkg/macros.h>
 
-#include <stdarg.h>
-#include <time.h>
+#include <cstdarg>
+#include <ctime>
 
 #include <string>
 #include <unordered_map>
diff --git a/apt-pkg/acquire-worker.cc b/apt-pkg/acquire-worker.cc
index 1bf07e82a..4f247cf84 100644
--- a/apt-pkg/acquire-worker.cc
+++ b/apt-pkg/acquire-worker.cc
@@ -28,11 +28,11 @@
 #include <string>
 #include <vector>
 
+#include <cerrno>
+#include <csignal>
+#include <cstdio>
+#include <cstdlib>
 #include <sstream>
-#include <errno.h>
-#include <signal.h>
-#include <stdio.h>
-#include <stdlib.h>
 #include <sys/stat.h>
 #include <unistd.h>
 
diff --git a/apt-pkg/acquire.cc b/apt-pkg/acquire.cc
index 1cb55bf14..7ebfa4ffe 100644
--- a/apt-pkg/acquire.cc
+++ b/apt-pkg/acquire.cc
@@ -35,14 +35,14 @@
 #include <tuple>
 #include <vector>
 
+#include <cerrno>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
 #include <dirent.h>
-#include <errno.h>
 #include <fcntl.h>
 #include <grp.h>
 #include <pwd.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
 #include <sys/select.h>
 #include <sys/stat.h>
 #include <sys/time.h>
diff --git a/apt-pkg/acquire.h b/apt-pkg/acquire.h
index f7c40aa5f..6eb9a6581 100644
--- a/apt-pkg/acquire.h
+++ b/apt-pkg/acquire.h
@@ -73,7 +73,7 @@
 #include <string>
 #include <vector>
 
-#include <stddef.h>
+#include <cstddef>
 #include <sys/select.h>
 #include <sys/time.h>
 
diff --git a/apt-pkg/algorithms.cc b/apt-pkg/algorithms.cc
index 24a41b70a..5869668cd 100644
--- a/apt-pkg/algorithms.cc
+++ b/apt-pkg/algorithms.cc
@@ -32,6 +32,7 @@
 #include <apt-pkg/prettyprinters.h>
 
 #include <cstdlib>
+#include <cstring>
 #include <iostream>
 #include <map>
 #include <set>
@@ -39,7 +40,6 @@
 #include <string>
 #include <utility>
 #include <vector>
-#include <string.h>
 #include <sys/utsname.h>
 
 #include <apti18n.h>
diff --git a/apt-pkg/aptconfiguration.cc b/apt-pkg/aptconfiguration.cc
index dbfa00bb3..982e68bb1 100644
--- a/apt-pkg/aptconfiguration.cc
+++ b/apt-pkg/aptconfiguration.cc
@@ -19,15 +19,15 @@
 #include <apt-pkg/strutl.h>
 
 #include <algorithm>
+#include <cctype>
+#include <cstddef>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
 #include <string>
 #include <vector>
-#include <ctype.h>
 #include <dirent.h>
 #include <fcntl.h>
-#include <stddef.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
 #include <sys/stat.h>
 #include <unistd.h>
 									/*}}}*/
diff --git a/apt-pkg/cachefile.cc b/apt-pkg/cachefile.cc
index 4c3cc9586..e27688b4e 100644
--- a/apt-pkg/cachefile.cc
+++ b/apt-pkg/cachefile.cc
@@ -27,13 +27,13 @@
 #include <apt-pkg/progress.h>
 #include <apt-pkg/sourcelist.h>
 
+#include <cstring>
 #include <limits>
 #include <memory>
 #include <string>
 #include <vector>
-#include <string.h>
-#include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/types.h>
 #include <unistd.h>
 
 #include <apti18n.h>
diff --git a/apt-pkg/cachefile.h b/apt-pkg/cachefile.h
index 4e26e6dab..cea802dc6 100644
--- a/apt-pkg/cachefile.h
+++ b/apt-pkg/cachefile.h
@@ -16,7 +16,7 @@
 #ifndef PKGLIB_CACHEFILE_H
 #define PKGLIB_CACHEFILE_H
 
-#include <stddef.h>
+#include <cstddef>
 
 #include <apt-pkg/depcache.h>
 #include <apt-pkg/macros.h>
diff --git a/apt-pkg/cachefilter-patterns.h b/apt-pkg/cachefilter-patterns.h
index fa4605253..1f2f4f781 100644
--- a/apt-pkg/cachefilter-patterns.h
+++ b/apt-pkg/cachefilter-patterns.h
@@ -14,12 +14,12 @@
 #include <apt-pkg/header-is-private.h>
 #include <apt-pkg/string_view.h>
 #include <apt-pkg/strutl.h>
+#include <cassert>
 #include <iostream>
 #include <memory>
 #include <sstream>
 #include <string>
 #include <vector>
-#include <assert.h>
 
 namespace APT
 {
diff --git a/apt-pkg/cachefilter.cc b/apt-pkg/cachefilter.cc
index eadbb98c7..e9334134f 100644
--- a/apt-pkg/cachefilter.cc
+++ b/apt-pkg/cachefilter.cc
@@ -14,11 +14,11 @@
 #include <apt-pkg/strutl.h>
 
 #include <algorithm>
+#include <cstring>
 #include <string>
 #include <unordered_map>
 #include <fnmatch.h>
 #include <regex.h>
-#include <string.h>
 
 #include <apti18n.h>
 									/*}}}*/
diff --git a/apt-pkg/cacheiterators.h b/apt-pkg/cacheiterators.h
index 074973048..9ed5c1719 100644
--- a/apt-pkg/cacheiterators.h
+++ b/apt-pkg/cacheiterators.h
@@ -39,7 +39,7 @@
 #include <string>
 #include <apt-pkg/string_view.h>
 
-#include <string.h>
+#include <cstring>
 
 // abstract Iterator template						/*{{{*/
 /* This template provides the very basic iterator methods we
diff --git a/apt-pkg/cacheset.cc b/apt-pkg/cacheset.cc
index ee0dcee28..bfc85ef49 100644
--- a/apt-pkg/cacheset.cc
+++ b/apt-pkg/cacheset.cc
@@ -25,13 +25,13 @@
 #include <apt-pkg/policy.h>
 #include <apt-pkg/versionmatch.h>
 
+#include <cstddef>
+#include <cstdio>
+#include <cstring>
 #include <list>
 #include <string>
 #include <vector>
 #include <regex.h>
-#include <stddef.h>
-#include <stdio.h>
-#include <string.h>
 
 #include <apti18n.h>
 									/*}}}*/
diff --git a/apt-pkg/cacheset.h b/apt-pkg/cacheset.h
index 4ea78bcae..5dbb9bf08 100644
--- a/apt-pkg/cacheset.h
+++ b/apt-pkg/cacheset.h
@@ -24,7 +24,7 @@
 #include <string>
 #include <vector>
 
-#include <stddef.h>
+#include <cstddef>
 
 #include <apt-pkg/error.h>
 #include <apt-pkg/macros.h>
diff --git a/apt-pkg/cdrom.cc b/apt-pkg/cdrom.cc
index ea10d10ad..70192a044 100644
--- a/apt-pkg/cdrom.cc
+++ b/apt-pkg/cdrom.cc
@@ -12,16 +12,15 @@
 #include <apt-pkg/strutl.h>
 
 #include <algorithm>
+#include <cstdio>
+#include <cstring>
 #include <fstream>
 #include <iostream>
-#include <iostream>
 #include <sstream>
 #include <string>
 #include <vector>
 #include <dirent.h>
 #include <dlfcn.h>
-#include <stdio.h>
-#include <string.h>
 #include <sys/stat.h>
 #include <unistd.h>
 
diff --git a/apt-pkg/cdrom.h b/apt-pkg/cdrom.h
index d3fc7710b..d5584dfab 100644
--- a/apt-pkg/cdrom.h
+++ b/apt-pkg/cdrom.h
@@ -6,8 +6,7 @@
 #include <string>
 #include <vector>
 
-#include <stddef.h>
-
+#include <cstddef>
 
 class Configuration;
 class OpProgress;
diff --git a/apt-pkg/clean.cc b/apt-pkg/clean.cc
index 9dd56e609..d3b0ac3ed 100644
--- a/apt-pkg/clean.cc
+++ b/apt-pkg/clean.cc
@@ -17,10 +17,10 @@
 #include <apt-pkg/pkgcache.h>
 #include <apt-pkg/strutl.h>
 
+#include <cstring>
 #include <string>
 #include <dirent.h>
 #include <fcntl.h>
-#include <string.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
diff --git a/apt-pkg/contrib/arfile.cc b/apt-pkg/contrib/arfile.cc
index 6d4a1f158..dfc380b77 100644
--- a/apt-pkg/contrib/arfile.cc
+++ b/apt-pkg/contrib/arfile.cc
@@ -20,8 +20,8 @@
 #include <apt-pkg/fileutl.h>
 #include <apt-pkg/strutl.h>
 
+#include <cstring>
 #include <string>
-#include <string.h>
 #include <sys/types.h>
 
 #include <apti18n.h>
diff --git a/apt-pkg/contrib/cdromutl.cc b/apt-pkg/contrib/cdromutl.cc
index f4020176a..5e2255fa3 100644
--- a/apt-pkg/contrib/cdromutl.cc
+++ b/apt-pkg/contrib/cdromutl.cc
@@ -18,14 +18,14 @@
 #include <apt-pkg/hashes.h>
 #include <apt-pkg/strutl.h>
 
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
 #include <iostream>
 #include <string>
 #include <vector>
 #include <dirent.h>
 #include <fcntl.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
 #include <sys/stat.h>
 #include <sys/statvfs.h>
 #include <unistd.h>
diff --git a/apt-pkg/contrib/cmndline.cc b/apt-pkg/contrib/cmndline.cc
index 998af2fd6..38f8521f9 100644
--- a/apt-pkg/contrib/cmndline.cc
+++ b/apt-pkg/contrib/cmndline.cc
@@ -21,10 +21,10 @@
 #include <apt-pkg/error.h>
 #include <apt-pkg/strutl.h>
 
+#include <cstddef>
+#include <cstdlib>
+#include <cstring>
 #include <string>
-#include <stddef.h>
-#include <stdlib.h>
-#include <string.h>
 
 #include <apti18n.h>
 									/*}}}*/
diff --git a/apt-pkg/contrib/configuration.cc b/apt-pkg/contrib/configuration.cc
index a5f97729c..abda6b66b 100644
--- a/apt-pkg/contrib/configuration.cc
+++ b/apt-pkg/contrib/configuration.cc
@@ -27,12 +27,12 @@
 #include <apt-pkg/strutl.h>
 #include <apt-pkg/string_view.h>
 
-#include <ctype.h>
+#include <cctype>
+#include <cstddef>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
 #include <regex.h>
-#include <stddef.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
 
 #include <algorithm>
 #include <array>
diff --git a/apt-pkg/contrib/error.cc b/apt-pkg/contrib/error.cc
index dd28af16d..c9bb622e7 100644
--- a/apt-pkg/contrib/error.cc
+++ b/apt-pkg/contrib/error.cc
@@ -23,15 +23,15 @@
 #include <apt-pkg/error.h>
 
 #include <algorithm>
+#include <cerrno>
+#include <cstdarg>
+#include <cstddef>
+#include <cstdio>
+#include <cstdlib>
 #include <cstring>
 #include <iostream>
 #include <list>
 #include <string>
-#include <errno.h>
-#include <stdarg.h>
-#include <stddef.h>
-#include <stdio.h>
-#include <stdlib.h>
 #include <unistd.h>
 
 									/*}}}*/
diff --git a/apt-pkg/contrib/error.h b/apt-pkg/contrib/error.h
index dd50b9cc4..35e39ee0e 100644
--- a/apt-pkg/contrib/error.h
+++ b/apt-pkg/contrib/error.h
@@ -49,8 +49,8 @@
 #include <list>
 #include <string>
 
-#include <stdarg.h>
-#include <stddef.h>
+#include <cstdarg>
+#include <cstddef>
 
 class APT_PUBLIC GlobalError						/*{{{*/
 {
diff --git a/apt-pkg/contrib/extracttar.cc b/apt-pkg/contrib/extracttar.cc
index dc2437528..96cc513f0 100644
--- a/apt-pkg/contrib/extracttar.cc
+++ b/apt-pkg/contrib/extracttar.cc
@@ -25,11 +25,11 @@
 #include <apt-pkg/strutl.h>
 
 #include <algorithm>
+#include <csignal>
+#include <cstring>
 #include <iostream>
 #include <string>
 #include <fcntl.h>
-#include <signal.h>
-#include <string.h>
 #include <unistd.h>
 
 #include <apti18n.h>
diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc
index 99b1df3ff..81e6fec85 100644
--- a/apt-pkg/contrib/fileutl.cc
+++ b/apt-pkg/contrib/fileutl.cc
@@ -35,28 +35,27 @@
 #include <apt-pkg/pkgsystem.h>
 #include <apt-pkg/strutl.h>
 
+#include <cctype>
+#include <cerrno>
+#include <csignal>
+#include <cstdarg>
+#include <cstddef>
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
+#include <ctime>
 #include <iostream>
 #include <string>
 #include <vector>
-#include <ctype.h>
 #include <dirent.h>
-#include <errno.h>
 #include <fcntl.h>
 #include <glob.h>
 #include <grp.h>
 #include <pwd.h>
-#include <signal.h>
-#include <stdarg.h>
-#include <stddef.h>
-#include <stdio.h>
 #include <sys/select.h>
 #include <sys/stat.h>
 #include <sys/time.h>
 #include <sys/wait.h>
-#include <time.h>
 #include <unistd.h>
 
 #include <algorithm>
@@ -81,8 +80,8 @@
 #ifdef HAVE_SYSTEMD
 #include <systemd/sd-bus.h>
 #endif
+#include <cstdint>
 #include <endian.h>
-#include <stdint.h>
 
 #if __gnu_linux__
 #include <sys/prctl.h>
diff --git a/apt-pkg/contrib/fileutl.h b/apt-pkg/contrib/fileutl.h
index 970b11878..11f4871f6 100644
--- a/apt-pkg/contrib/fileutl.h
+++ b/apt-pkg/contrib/fileutl.h
@@ -27,11 +27,11 @@
 #include <apt-pkg/aptconfiguration.h>
 #include <apt-pkg/macros.h>
 
+#include <ctime>
 #include <set>
 #include <string>
 #include <vector>
 #include <sys/stat.h>
-#include <time.h>
 
 /* Define this for python-apt */
 #define APT_HAS_GZIP 1
diff --git a/apt-pkg/contrib/gpgv.cc b/apt-pkg/contrib/gpgv.cc
index 3368ece84..2fa5b0c30 100644
--- a/apt-pkg/contrib/gpgv.cc
+++ b/apt-pkg/contrib/gpgv.cc
@@ -8,12 +8,12 @@
 #include <apt-pkg/gpgv.h>
 #include <apt-pkg/strutl.h>
 
-#include <errno.h>
+#include <cerrno>
+#include <cstddef>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
 #include <fcntl.h>
-#include <stddef.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
diff --git a/apt-pkg/contrib/hashes.cc b/apt-pkg/contrib/hashes.cc
index 313b1d37d..7ff5f9e9f 100644
--- a/apt-pkg/contrib/hashes.cc
+++ b/apt-pkg/contrib/hashes.cc
@@ -21,11 +21,11 @@
 #include <apt-pkg/tagfile.h>
 
 #include <algorithm>
+#include <cassert>
+#include <cstddef>
+#include <cstdlib>
 #include <iostream>
 #include <string>
-#include <assert.h>
-#include <stddef.h>
-#include <stdlib.h>
 #include <unistd.h>
 
 #include <gcrypt.h>
diff --git a/apt-pkg/contrib/mmap.cc b/apt-pkg/contrib/mmap.cc
index 0568e1cd0..56e0801f6 100644
--- a/apt-pkg/contrib/mmap.cc
+++ b/apt-pkg/contrib/mmap.cc
@@ -23,11 +23,11 @@
 #include <apt-pkg/macros.h>
 #include <apt-pkg/mmap.h>
 
+#include <cerrno>
 #include <cstdint>
+#include <cstdlib>
 #include <cstring>
 #include <string>
-#include <errno.h>
-#include <stdlib.h>
 #include <unistd.h>
 
 #include <apti18n.h>
diff --git a/apt-pkg/contrib/progress.cc b/apt-pkg/contrib/progress.cc
index eb688b9a2..a2c4332ca 100644
--- a/apt-pkg/contrib/progress.cc
+++ b/apt-pkg/contrib/progress.cc
@@ -13,12 +13,12 @@
 #include <apt-pkg/error.h>
 #include <apt-pkg/progress.h>
 
-#include <cmath>
 #include <chrono>
+#include <cmath>
+#include <cstdio>
 #include <cstring>
 #include <iostream>
 #include <string>
-#include <stdio.h>
 #include <sys/time.h>
 
 #include <apti18n.h>
diff --git a/apt-pkg/contrib/srvrec.cc b/apt-pkg/contrib/srvrec.cc
index 3eb5f1d4c..4a68f3578 100644
--- a/apt-pkg/contrib/srvrec.cc
+++ b/apt-pkg/contrib/srvrec.cc
@@ -10,11 +10,11 @@
 
 #include <netdb.h>
 
-#include <arpa/nameser.h>
+#include <ctime>
 #include <arpa/inet.h>
+#include <arpa/nameser.h>
 #include <netinet/in.h>
 #include <resolv.h>
-#include <time.h>
 
 #include <algorithm>
 #include <memory>
diff --git a/apt-pkg/contrib/string_view.h b/apt-pkg/contrib/string_view.h
index 04f6ff115..71f47f563 100644
--- a/apt-pkg/contrib/string_view.h
+++ b/apt-pkg/contrib/string_view.h
@@ -12,8 +12,8 @@
 #if !defined(APT_STRINGVIEW_H)
 #define APT_STRINGVIEW_H
 #include <apt-pkg/macros.h>
+#include <cstring>
 #include <string>
-#include <string.h>
 
 namespace APT {
 
diff --git a/apt-pkg/contrib/strutl.cc b/apt-pkg/contrib/strutl.cc
index 67100f1a2..3689dc17a 100644
--- a/apt-pkg/contrib/strutl.cc
+++ b/apt-pkg/contrib/strutl.cc
@@ -35,18 +35,18 @@
 #include <string>
 #include <vector>
 
-#include <ctype.h>
-#include <errno.h>
+#include <cctype>
+#include <cerrno>
+#include <cstdarg>
+#include <cstddef>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <ctime>
+#include <cwchar>
 #include <iconv.h>
 #include <regex.h>
-#include <stdarg.h>
-#include <stddef.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <time.h>
 #include <unistd.h>
-#include <wchar.h>
 
 #include <apti18n.h>
 									/*}}}*/
diff --git a/apt-pkg/contrib/strutl.h b/apt-pkg/contrib/strutl.h
index 1fdc8dc99..7cf9b456d 100644
--- a/apt-pkg/contrib/strutl.h
+++ b/apt-pkg/contrib/strutl.h
@@ -19,14 +19,14 @@
 #ifndef STRUTL_H
 #define STRUTL_H
 
+#include <apt-pkg/string_view.h>
+#include <cstddef>
 #include <cstring>
+#include <ctime>
 #include <iostream>
 #include <limits>
 #include <string>
 #include <vector>
-#include <apt-pkg/string_view.h>
-#include <stddef.h>
-#include <time.h>
 
 #include "macros.h"
 
diff --git a/apt-pkg/contrib/weakptr.h b/apt-pkg/contrib/weakptr.h
index 8de727d89..6cfa948ac 100644
--- a/apt-pkg/contrib/weakptr.h
+++ b/apt-pkg/contrib/weakptr.h
@@ -21,8 +21,8 @@
 #ifndef WEAK_POINTER_H
 #define WEAK_POINTER_H
 
+#include <cstddef>
 #include <set>
-#include <stddef.h>
 
 /**
  * Class for objects providing support for weak pointers.
diff --git a/apt-pkg/deb/debfile.cc b/apt-pkg/deb/debfile.cc
index 645a579ef..1d61c8227 100644
--- a/apt-pkg/deb/debfile.cc
+++ b/apt-pkg/deb/debfile.cc
@@ -28,10 +28,10 @@
 #include <apt-pkg/tagfile.h>
 
 #include <algorithm>
-#include <string>
+#include <cstring>
 #include <sstream>
+#include <string>
 #include <vector>
-#include <string.h>
 #include <sys/stat.h>
 
 #include <apti18n.h>
diff --git a/apt-pkg/deb/debindexfile.cc b/apt-pkg/deb/debindexfile.cc
index e1698e151..c4115e53e 100644
--- a/apt-pkg/deb/debindexfile.cc
+++ b/apt-pkg/deb/debindexfile.cc
@@ -25,11 +25,11 @@
 #include <apt-pkg/srcrecords.h>
 #include <apt-pkg/strutl.h>
 
+#include <cstdio>
 #include <iostream>
 #include <memory>
 #include <sstream>
 #include <string>
-#include <stdio.h>
 
 #include <sys/stat.h>
 #include <unistd.h>
diff --git a/apt-pkg/deb/deblistparser.cc b/apt-pkg/deb/deblistparser.cc
index 6b76c4d07..8099b36e4 100644
--- a/apt-pkg/deb/deblistparser.cc
+++ b/apt-pkg/deb/deblistparser.cc
@@ -25,11 +25,11 @@
 #include <apt-pkg/tagfile.h>
 
 #include <algorithm>
+#include <cctype>
+#include <cstddef>
+#include <cstring>
 #include <string>
 #include <vector>
-#include <ctype.h>
-#include <stddef.h>
-#include <string.h>
 									/*}}}*/
 
 using std::string;
diff --git a/apt-pkg/deb/debmetaindex.cc b/apt-pkg/deb/debmetaindex.cc
index 3fef976e9..0f05cb21a 100644
--- a/apt-pkg/deb/debmetaindex.cc
+++ b/apt-pkg/deb/debmetaindex.cc
@@ -24,7 +24,7 @@
 #include <utility>
 #include <vector>
 
-#include <string.h>
+#include <cstring>
 #include <sys/stat.h>
 
 #include <apti18n.h>
diff --git a/apt-pkg/deb/debrecords.cc b/apt-pkg/deb/debrecords.cc
index e2ffaefff..b9d1b6e2f 100644
--- a/apt-pkg/deb/debrecords.cc
+++ b/apt-pkg/deb/debrecords.cc
@@ -20,11 +20,11 @@
 #include <apt-pkg/tagfile.h>
 
 #include <algorithm>
+#include <cstring>
 #include <sstream>
 #include <string>
 #include <vector>
 #include <langinfo.h>
-#include <string.h>
 
 #include <apti18n.h>
 									/*}}}*/
diff --git a/apt-pkg/deb/debsrcrecords.cc b/apt-pkg/deb/debsrcrecords.cc
index 311bacfdd..ab78b88ce 100644
--- a/apt-pkg/deb/debsrcrecords.cc
+++ b/apt-pkg/deb/debsrcrecords.cc
@@ -22,12 +22,12 @@
 #include <apt-pkg/tagfile.h>
 
 #include <algorithm>
-#include <string>
+#include <cctype>
+#include <cstdlib>
+#include <cstring>
 #include <sstream>
+#include <string>
 #include <vector>
-#include <ctype.h>
-#include <stdlib.h>
-#include <string.h>
 									/*}}}*/
 
 using std::max;
diff --git a/apt-pkg/deb/debsrcrecords.h b/apt-pkg/deb/debsrcrecords.h
index 1a0bbe0fd..6ba30c2ac 100644
--- a/apt-pkg/deb/debsrcrecords.h
+++ b/apt-pkg/deb/debsrcrecords.h
@@ -15,9 +15,9 @@
 #include <apt-pkg/tagfile-keys.h>
 #include <apt-pkg/tagfile.h>
 
+#include <cstddef>
 #include <string>
 #include <vector>
-#include <stddef.h>
 
 class pkgIndexFile;
 
diff --git a/apt-pkg/deb/debsystem.cc b/apt-pkg/deb/debsystem.cc
index 9c55e0a6e..a218005dc 100644
--- a/apt-pkg/deb/debsystem.cc
+++ b/apt-pkg/deb/debsystem.cc
@@ -24,14 +24,14 @@
 #include <algorithm>
 #include <sstream>
 
+#include <cctype>
+#include <cerrno>
+#include <cstdlib>
+#include <cstring>
 #include <string>
 #include <vector>
-#include <ctype.h>
 #include <dirent.h>
-#include <errno.h>
 #include <fcntl.h>
-#include <stdlib.h>
-#include <string.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/wait.h>
diff --git a/apt-pkg/deb/debversion.cc b/apt-pkg/deb/debversion.cc
index 005f1bce0..ec7c9538e 100644
--- a/apt-pkg/deb/debversion.cc
+++ b/apt-pkg/deb/debversion.cc
@@ -14,9 +14,9 @@
 #include <apt-pkg/debversion.h>
 #include <apt-pkg/pkgcache.h>
 
-#include <ctype.h>
-#include <stdlib.h>
-#include <string.h>
+#include <cctype>
+#include <cstdlib>
+#include <cstring>
 									/*}}}*/
 
 debVersioningSystem debVS;
diff --git a/apt-pkg/deb/dpkgpm.cc b/apt-pkg/deb/dpkgpm.cc
index 93effa959..4f87cc22b 100644
--- a/apt-pkg/deb/dpkgpm.cc
+++ b/apt-pkg/deb/dpkgpm.cc
@@ -24,15 +24,16 @@
 #include <apt-pkg/strutl.h>
 #include <apt-pkg/version.h>
 
+#include <cerrno>
+#include <csignal>
+#include <cstddef>
+#include <cstdio>
+#include <cstdlib>
+#include <ctime>
 #include <dirent.h>
-#include <errno.h>
 #include <fcntl.h>
 #include <grp.h>
 #include <pwd.h>
-#include <signal.h>
-#include <stddef.h>
-#include <stdio.h>
-#include <stdlib.h>
 #include <sys/ioctl.h>
 #include <sys/select.h>
 #include <sys/stat.h>
@@ -40,7 +41,6 @@
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <termios.h>
-#include <time.h>
 #include <unistd.h>
 
 #include <algorithm>
diff --git a/apt-pkg/deb/dpkgpm.h b/apt-pkg/deb/dpkgpm.h
index caf7d3512..ed0b67b31 100644
--- a/apt-pkg/deb/dpkgpm.h
+++ b/apt-pkg/deb/dpkgpm.h
@@ -13,11 +13,10 @@
 #include <apt-pkg/packagemanager.h>
 #include <apt-pkg/pkgcache.h>
 
+#include <cstdio>
 #include <map>
 #include <string>
 #include <vector>
-#include <stdio.h>
-
 
 class pkgDepCache;
 namespace APT { namespace Progress { class PackageManager; } }
diff --git a/apt-pkg/depcache.cc b/apt-pkg/depcache.cc
index c965781a4..e3e8d627c 100644
--- a/apt-pkg/depcache.cc
+++ b/apt-pkg/depcache.cc
@@ -29,6 +29,8 @@
 #include <apt-pkg/versionmatch.h>
 
 #include <algorithm>
+#include <cstdio>
+#include <cstring>
 #include <iostream>
 #include <iterator>
 #include <list>
@@ -40,8 +42,6 @@
 #include <unordered_map>
 #include <utility>
 #include <vector>
-#include <stdio.h>
-#include <string.h>
 
 #include <sys/stat.h>
 
diff --git a/apt-pkg/depcache.h b/apt-pkg/depcache.h
index a850cf91a..5dd022b56 100644
--- a/apt-pkg/depcache.h
+++ b/apt-pkg/depcache.h
@@ -41,7 +41,7 @@
 #include <apt-pkg/macros.h>
 #include <apt-pkg/pkgcache.h>
 
-#include <stddef.h>
+#include <cstddef>
 
 #include <list>
 #include <memory>
diff --git a/apt-pkg/dirstream.cc b/apt-pkg/dirstream.cc
index d6cf0ab3f..ef9f08ebc 100644
--- a/apt-pkg/dirstream.cc
+++ b/apt-pkg/dirstream.cc
@@ -15,7 +15,7 @@
 #include <apt-pkg/dirstream.h>
 #include <apt-pkg/error.h>
 
-#include <errno.h>
+#include <cerrno>
 #include <fcntl.h>
 #include <sys/stat.h>
 #include <sys/time.h>
diff --git a/apt-pkg/edsp.cc b/apt-pkg/edsp.cc
index 9d196eed3..b0ac4ae49 100644
--- a/apt-pkg/edsp.cc
+++ b/apt-pkg/edsp.cc
@@ -23,10 +23,10 @@
 #include <apt-pkg/strutl.h>
 #include <apt-pkg/tagfile.h>
 
-#include <ctype.h>
-#include <stddef.h>
-#include <stdio.h>
-#include <string.h>
+#include <cctype>
+#include <cstddef>
+#include <cstdio>
+#include <cstring>
 #include <sys/stat.h>
 #include <unistd.h>
 
diff --git a/apt-pkg/edsp.h b/apt-pkg/edsp.h
index 434010dc4..0c37e231d 100644
--- a/apt-pkg/edsp.h
+++ b/apt-pkg/edsp.h
@@ -13,7 +13,7 @@
 #include <apt-pkg/macros.h>
 #include <apt-pkg/pkgcache.h>
 
-#include <stdio.h>
+#include <cstdio>
 
 #include <list>
 #include <string>
diff --git a/apt-pkg/edsp/edspindexfile.cc b/apt-pkg/edsp/edspindexfile.cc
index faade6e0a..e97f16894 100644
--- a/apt-pkg/edsp/edspindexfile.cc
+++ b/apt-pkg/edsp/edspindexfile.cc
@@ -16,9 +16,9 @@
 #include <apt-pkg/pkgcache.h>
 #include <apt-pkg/pkgrecords.h>
 
+#include <cstddef>
 #include <memory>
 #include <string>
-#include <stddef.h>
 #include <unistd.h>
 									/*}}}*/
 
diff --git a/apt-pkg/edsp/edspsystem.cc b/apt-pkg/edsp/edspsystem.cc
index c86f1ed3f..b12b20da8 100644
--- a/apt-pkg/edsp/edspsystem.cc
+++ b/apt-pkg/edsp/edspsystem.cc
@@ -18,8 +18,8 @@
 #include <apt-pkg/fileutl.h>
 #include <apt-pkg/pkgcache.h>
 
-#include <stddef.h>
-#include <stdlib.h>
+#include <cstddef>
+#include <cstdlib>
 #include <unistd.h>
 
 #include <string>
diff --git a/apt-pkg/indexcopy.cc b/apt-pkg/indexcopy.cc
index 0d569265d..bf787036f 100644
--- a/apt-pkg/indexcopy.cc
+++ b/apt-pkg/indexcopy.cc
@@ -25,11 +25,11 @@
 #include <apt-pkg/tagfile-keys.h>
 #include <apt-pkg/tagfile.h>
 
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
 #include <iostream>
 #include <sstream>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
 #include <sys/stat.h>
 #include <unistd.h>
 
diff --git a/apt-pkg/indexcopy.h b/apt-pkg/indexcopy.h
index 41be15498..5fcce20d0 100644
--- a/apt-pkg/indexcopy.h
+++ b/apt-pkg/indexcopy.h
@@ -11,8 +11,8 @@
 
 #include <vector>
 #ifndef APT_11_CLEAN_HEADERS
+#include <cstdio>
 #include <string>
-#include <stdio.h>
 #endif
 
 #include <apt-pkg/macros.h>
diff --git a/apt-pkg/init.cc b/apt-pkg/init.cc
index 3990a1f39..f1742c019 100644
--- a/apt-pkg/init.cc
+++ b/apt-pkg/init.cc
@@ -18,12 +18,12 @@
 #include <apt-pkg/strutl.h>
 
 #include <cstdlib>
+#include <cstring>
 #include <fstream>
 #include <sstream>
 #include <string>
 #include <unordered_map>
 #include <vector>
-#include <string.h>
 
 #include <apti18n.h>
 									/*}}}*/
diff --git a/apt-pkg/install-progress.cc b/apt-pkg/install-progress.cc
index c7f7573de..2b0dc21ea 100644
--- a/apt-pkg/install-progress.cc
+++ b/apt-pkg/install-progress.cc
@@ -7,12 +7,12 @@
 
 #include <algorithm>
 #include <cmath>
+#include <csignal>
+#include <cstdio>
 #include <iostream>
 #include <sstream>
 #include <vector>
 #include <fcntl.h>
-#include <signal.h>
-#include <stdio.h>
 #include <sys/ioctl.h>
 #include <unistd.h>
 
diff --git a/apt-pkg/install-progress.h b/apt-pkg/install-progress.h
index 617ce2a35..db060b3bc 100644
--- a/apt-pkg/install-progress.h
+++ b/apt-pkg/install-progress.h
@@ -3,9 +3,9 @@
 
 #include <apt-pkg/macros.h>
 
+#include <csignal>
 #include <string>
 #include <vector>
-#include <signal.h>
 #include <unistd.h>
 
 namespace APT {
diff --git a/apt-pkg/metaindex.h b/apt-pkg/metaindex.h
index 3e9cf3718..e2a773c31 100644
--- a/apt-pkg/metaindex.h
+++ b/apt-pkg/metaindex.h
@@ -4,7 +4,7 @@
 #include <apt-pkg/indexfile.h>
 #include <apt-pkg/init.h>
 
-#include <stddef.h>
+#include <cstddef>
 
 #include <string>
 #include <vector>
diff --git a/apt-pkg/orderlist.cc b/apt-pkg/orderlist.cc
index 49a3126b7..33d17fcec 100644
--- a/apt-pkg/orderlist.cc
+++ b/apt-pkg/orderlist.cc
@@ -71,9 +71,9 @@
 #include <apt-pkg/pkgcache.h>
 
 #include <algorithm>
+#include <cstdlib>
+#include <cstring>
 #include <iostream>
-#include <stdlib.h>
-#include <string.h>
 									/*}}}*/
 
 using namespace std;
diff --git a/apt-pkg/packagemanager.cc b/apt-pkg/packagemanager.cc
index 48dd03f66..ce7677e83 100644
--- a/apt-pkg/packagemanager.cc
+++ b/apt-pkg/packagemanager.cc
@@ -29,10 +29,10 @@
 #include <apt-pkg/strutl.h>
 #include <apt-pkg/version.h>
 
+#include <cstddef>
 #include <iostream>
 #include <list>
 #include <string>
-#include <stddef.h>
 
 #include <apti18n.h>
 									/*}}}*/
diff --git a/apt-pkg/pkgcache.cc b/apt-pkg/pkgcache.cc
index 06689aa33..ffe30fa92 100644
--- a/apt-pkg/pkgcache.cc
+++ b/apt-pkg/pkgcache.cc
@@ -32,11 +32,11 @@
 #include <apt-pkg/version.h>
 
 #include <algorithm>
+#include <cstddef>
+#include <cstring>
 #include <sstream>
 #include <string>
 #include <vector>
-#include <stddef.h>
-#include <string.h>
 #include <sys/stat.h>
 #include <xxhash.h>
 
diff --git a/apt-pkg/pkgcache.h b/apt-pkg/pkgcache.h
index 55baa3cef..7c16f0dee 100644
--- a/apt-pkg/pkgcache.h
+++ b/apt-pkg/pkgcache.h
@@ -77,10 +77,10 @@
 #include <apt-pkg/macros.h>
 #include <apt-pkg/mmap.h>
 
-#include <cstddef>       // required for nullptr_t
+#include <cstddef> // required for nullptr_t
+#include <cstdint>
+#include <ctime>
 #include <string>
-#include <stdint.h>
-#include <time.h>
 
 #include <apt-pkg/string_view.h>
 
diff --git a/apt-pkg/pkgcachegen.cc b/apt-pkg/pkgcachegen.cc
index 3a85a9585..504756104 100644
--- a/apt-pkg/pkgcachegen.cc
+++ b/apt-pkg/pkgcachegen.cc
@@ -27,12 +27,12 @@
 #include <apt-pkg/version.h>
 
 #include <algorithm>
+#include <cstddef>
+#include <cstring>
 #include <iostream>
 #include <memory>
 #include <string>
 #include <vector>
-#include <stddef.h>
-#include <string.h>
 #include <sys/stat.h>
 #include <unistd.h>
 
diff --git a/apt-pkg/pkgrecords.cc b/apt-pkg/pkgrecords.cc
index 77aa8ce1b..83d19bb8b 100644
--- a/apt-pkg/pkgrecords.cc
+++ b/apt-pkg/pkgrecords.cc
@@ -15,8 +15,8 @@
 #include <apt-pkg/pkgcache.h>
 #include <apt-pkg/pkgrecords.h>
 
+#include <cstddef>
 #include <vector>
-#include <stddef.h>
 
 #include <apti18n.h>
 									/*}}}*/
diff --git a/apt-pkg/policy.cc b/apt-pkg/policy.cc
index 68b3f5e5f..b1d8e7223 100644
--- a/apt-pkg/policy.cc
+++ b/apt-pkg/policy.cc
@@ -28,17 +28,17 @@
 #include <apt-pkg/version.h>
 #include <apt-pkg/versionmatch.h>
 
+#include <cctype>
+#include <cstddef>
+#include <cstring>
 #include <iostream>
 #include <random>
 #include <sstream>
 #include <string>
 #include <vector>
-#include <ctype.h>
-#include <stddef.h>
-#include <string.h>
 
 #include <apti18n.h>
-									/*}}}*/
+   /*}}}*/
 
 using namespace std;
 
diff --git a/apt-pkg/sourcelist.cc b/apt-pkg/sourcelist.cc
index e11afceed..65412b458 100644
--- a/apt-pkg/sourcelist.cc
+++ b/apt-pkg/sourcelist.cc
@@ -23,14 +23,14 @@
 #include <apt-pkg/tagfile.h>
 
 #include <algorithm>
+#include <cctype>
+#include <cstddef>
 #include <cstring>
+#include <ctime>
 #include <fstream>
 #include <map>
 #include <string>
 #include <vector>
-#include <ctype.h>
-#include <stddef.h>
-#include <time.h>
 
 #include <apti18n.h>
 									/*}}}*/
diff --git a/apt-pkg/sourcelist.h b/apt-pkg/sourcelist.h
index 454180371..2d7018824 100644
--- a/apt-pkg/sourcelist.h
+++ b/apt-pkg/sourcelist.h
@@ -25,7 +25,7 @@
 #include <apt-pkg/macros.h>
 #include <apt-pkg/pkgcache.h>
 
-#include <time.h>
+#include <ctime>
 
 #include <map>
 #include <string>
diff --git a/apt-pkg/srcrecords.cc b/apt-pkg/srcrecords.cc
index 03bda75e9..f2511b37b 100644
--- a/apt-pkg/srcrecords.cc
+++ b/apt-pkg/srcrecords.cc
@@ -20,9 +20,9 @@
 #include <apt-pkg/sourcelist.h>
 #include <apt-pkg/srcrecords.h>
 
+#include <cstring>
 #include <string>
 #include <vector>
-#include <string.h>
 
 #include <apti18n.h>
 									/*}}}*/
diff --git a/apt-pkg/tagfile.cc b/apt-pkg/tagfile.cc
index 047f88986..8f323bb5a 100644
--- a/apt-pkg/tagfile.cc
+++ b/apt-pkg/tagfile.cc
@@ -21,11 +21,11 @@
 
 #include <list>
 
+#include <cctype>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
 #include <string>
-#include <ctype.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
 
 #include <apti18n.h>
 									/*}}}*/
diff --git a/apt-pkg/tagfile.h b/apt-pkg/tagfile.h
index a9f581424..0020d284b 100644
--- a/apt-pkg/tagfile.h
+++ b/apt-pkg/tagfile.h
@@ -21,8 +21,8 @@
 
 #include <apt-pkg/macros.h>
 
-#include <stdint.h>
-#include <stdio.h>
+#include <cstdint>
+#include <cstdio>
 
 #include <list>
 #include <string>
diff --git a/apt-pkg/upgrade.h b/apt-pkg/upgrade.h
index 8e8960197..00914a190 100644
--- a/apt-pkg/upgrade.h
+++ b/apt-pkg/upgrade.h
@@ -11,7 +11,7 @@
 #define PKGLIB_UPGRADE_H
 
 #include <apt-pkg/macros.h>
-#include <stddef.h>
+#include <cstddef>
 
 class pkgDepCache;
 class OpProgress;
diff --git a/apt-pkg/version.cc b/apt-pkg/version.cc
index e0b83e0cd..df01507e0 100644
--- a/apt-pkg/version.cc
+++ b/apt-pkg/version.cc
@@ -11,8 +11,8 @@
 
 #include <apt-pkg/version.h>
 
-#include <stdlib.h>
-#include <string.h>
+#include <cstdlib>
+#include <cstring>
 									/*}}}*/
     
 static pkgVersioningSystem *VSList[10];
diff --git a/apt-pkg/versionmatch.cc b/apt-pkg/versionmatch.cc
index 83a969c4a..f95232ac3 100644
--- a/apt-pkg/versionmatch.cc
+++ b/apt-pkg/versionmatch.cc
@@ -17,14 +17,14 @@
 #include <apt-pkg/strutl.h>
 #include <apt-pkg/versionmatch.h>
 
+#include <cctype>
+#include <cstddef>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
 #include <string>
-#include <ctype.h>
 #include <fnmatch.h>
 #include <regex.h>
-#include <stddef.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
 									/*}}}*/
 
 using std::string;