Index: clang-tidy/modernize/DeprecatedHeadersCheck.cpp
===================================================================
--- clang-tidy/modernize/DeprecatedHeadersCheck.cpp
+++ clang-tidy/modernize/DeprecatedHeadersCheck.cpp
@@ -13,6 +13,7 @@
 #include "clang/Lex/Preprocessor.h"
 #include "llvm/ADT/StringMap.h"
 
+#include <set>
 #include <vector>
 
 namespace clang {
@@ -35,6 +36,7 @@
   ClangTidyCheck &Check;
   LangOptions LangOpts;
   llvm::StringMap<std::string> CStyledHeaderToCxx;
+  std::set<std::string> DeleteHeader;
 };
 } // namespace
 
@@ -51,16 +53,23 @@
     : Check(Check), LangOpts(LangOpts) {
   for (const auto &KeyValue :
        std::vector<std::pair<llvm::StringRef, std::string>>(
-           {{"assert.h", "cassert"}, {"complex.h", "ccomplex"},
-            {"ctype.h", "cctype"},   {"errno.h", "cerrno"},
-            {"float.h", "cfloat"},   {"inttypes.h", "cinttypes"},
-            {"iso646.h", "ciso646"}, {"limits.h", "climits"},
-            {"locale.h", "clocale"}, {"math.h", "cmath"},
-            {"setjmp.h", "csetjmp"}, {"signal.h", "csignal"},
-            {"stdarg.h", "cstdarg"}, {"stddef.h", "cstddef"},
-            {"stdint.h", "cstdint"}, {"stdio.h", "cstdio"},
-            {"stdlib.h", "cstdlib"}, {"string.h", "cstring"},
-            {"time.h", "ctime"},     {"wchar.h", "cwchar"},
+           {{"assert.h", "cassert"},
+            {"complex.h", "complex"},
+            {"ctype.h", "cctype"},
+            {"errno.h", "cerrno"},
+            {"float.h", "cfloat"},
+            {"limits.h", "climits"},
+            {"locale.h", "clocale"},
+            {"math.h", "cmath"},
+            {"setjmp.h", "csetjmp"},
+            {"signal.h", "csignal"},
+            {"stdarg.h", "cstdarg"},
+            {"stddef.h", "cstddef"},
+            {"stdio.h", "cstdio"},
+            {"stdlib.h", "cstdlib"},
+            {"string.h", "cstring"},
+            {"time.h", "ctime"},
+            {"wchar.h", "cwchar"},
             {"wctype.h", "cwctype"}})) {
     CStyledHeaderToCxx.insert(KeyValue);
   }
@@ -69,13 +78,14 @@
     for (const auto &KeyValue :
          std::vector<std::pair<llvm::StringRef, std::string>>(
              {{"fenv.h", "cfenv"},
-              {"stdalign.h", "cstdalign"},
-              {"stdbool.h", "cstdbool"},
+              {"stdint.h", "cstdint"},
+              {"inttypes.h", "cinttypes"},
               {"tgmath.h", "ctgmath"},
               {"uchar.h", "cuchar"}})) {
       CStyledHeaderToCxx.insert(KeyValue);
     }
   }
+  DeleteHeader = {"stdalign.h", "stdbool.h", "iso646.h"};
 }
 
 void IncludeModernizePPCallbacks::InclusionDirective(
@@ -92,11 +102,16 @@
   if (CStyledHeaderToCxx.count(FileName) != 0) {
     std::string Replacement =
         (llvm::Twine("<") + CStyledHeaderToCxx[FileName] + ">").str();
-    Check.diag(FilenameRange.getBegin(),
-               "inclusion of deprecated C++ header '%0'; consider using '%1' instead")
+    Check.diag(
+        FilenameRange.getBegin(),
+        "inclusion of deprecated C++ header '%0'; consider using '%1' instead")
         << FileName << CStyledHeaderToCxx[FileName]
         << FixItHint::CreateReplacement(FilenameRange.getAsRange(),
                                         Replacement);
+  } else if (DeleteHeader.count(FileName) != 0) {
+    Check.diag(FilenameRange.getBegin(),
+               "including '%0' has no effect in C++; consider removing it")
+        << FileName << FixItHint::CreateRemoval(FilenameRange.getAsRange());
   }
 }
 
Index: docs/clang-tidy/checks/modernize-deprecated-headers.rst
===================================================================
--- docs/clang-tidy/checks/modernize-deprecated-headers.rst
+++ docs/clang-tidy/checks/modernize-deprecated-headers.rst
@@ -4,10 +4,11 @@
 ============================
 
 Some headers from C library were deprecated in C++ and are no longer welcome in
-C++ codebases. For more details refer to the C++ 14 Standard [depr.c.headers]
-section.
+C++ codebases. Some have no effect in C++. For more details refer to the C++ 14
+Standard [depr.c.headers] section.
 
-This check replaces C standard library headers with their C++ alternatives.
+This check replaces C standard library headers with their C++ alternatives and
+removes redundant ones.
 
 Improtant note: the Standard doesn't guarantee that the C++ headers declare all
 the same functions in the global namespace. The check in its current form can
@@ -20,15 +21,12 @@
 * `<fenv.h>`     // deprecated since C++11
 * `<float.h>`
 * `<inttypes.h>`
-* `<iso646.h>`
 * `<limits.h>`
 * `<locale.h>`
 * `<math.h>`
 * `<setjmp.h>`
 * `<signal.h>`
-* `<stdalign.h>` // deprecated since C++11
 * `<stdarg.h>`
-* `<stdbool.h>`  // deprecated since C++11
 * `<stddef.h>`
 * `<stdint.h>`
 * `<stdio.h>`
@@ -42,4 +40,10 @@
 
 If the specified standard is older than C++11 the check will only replace
 headers deprecated before C++11, otherwise -- every header that appeared in
-the list.
+previous list.
+
+These checks don't have effect in C++:
+
+* `<iso646.h>`
+* `<stdalign.h>`
+* `<stdbool.h>`
Index: test/clang-tidy/modernize-deprecated-headers-cxx03.cpp
===================================================================
--- test/clang-tidy/modernize-deprecated-headers-cxx03.cpp
+++ test/clang-tidy/modernize-deprecated-headers-cxx03.cpp
@@ -5,8 +5,6 @@
 #include <ctype.h>
 #include <errno.h>
 #include <float.h>
-#include <inttypes.h>
-#include <iso646.h>
 #include <limits.h>
 #include <locale.h>
 #include <math.h>
@@ -14,7 +12,6 @@
 #include <signal.h>
 #include <stdarg.h>
 #include <stddef.h>
-#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -22,42 +19,47 @@
 #include <wchar.h>
 #include <wctype.h>
 
-// Headers deprecated since C++11: expect no diagnostics.
-#include <fenv.h>
+// Headers that have no effect in C++; remove them
 #include <stdalign.h>
 #include <stdbool.h>
+#include <iso646.h>
+
+// Headers deprecated since C++11: expect no diagnostics.
+#include <fenv.h>
+#include <inttypes.h>
+#include <stdint.h>
 #include <tgmath.h>
 #include <uchar.h>
 
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'assert.h'; consider using 'cassert' instead [modernize-deprecated-headers]
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'complex.h'; consider using 'ccomplex' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'ctype.h'; consider using 'cctype' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'errno.h'; consider using 'cerrno' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'float.h'; consider using 'cfloat' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'inttypes.h'; consider using 'cinttypes' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'iso646.h'; consider using 'ciso646' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'limits.h'; consider using 'climits' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'locale.h'; consider using 'clocale' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'math.h'; consider using 'cmath' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'setjmp.h'; consider using 'csetjmp' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'signal.h'; consider using 'csignal' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'stdarg.h'; consider using 'cstdarg' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'stddef.h'; consider using 'cstddef' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'stdint.h'; consider using 'cstdint' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'stdio.h'; consider using 'cstdio' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'stdlib.h'; consider using 'cstdlib' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'string.h'; consider using 'cstring' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'time.h'; consider using 'ctime' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'wchar.h'; consider using 'cwchar' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'wctype.h'; consider using 'cwctype' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'assert.h'; consider using 'cassert' instead [modernize-deprecated-headers]
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'complex.h'; consider using 'complex' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'ctype.h'; consider using 'cctype' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'errno.h'; consider using 'cerrno' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'float.h'; consider using 'cfloat' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'limits.h'; consider using 'climits' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'locale.h'; consider using 'clocale' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'math.h'; consider using 'cmath' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'setjmp.h'; consider using 'csetjmp' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'signal.h'; consider using 'csignal' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'stdarg.h'; consider using 'cstdarg' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'stddef.h'; consider using 'cstddef' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'stdio.h'; consider using 'cstdio' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'stdlib.h'; consider using 'cstdlib' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'string.h'; consider using 'cstring' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'time.h'; consider using 'ctime' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'wchar.h'; consider using 'cwchar' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'wctype.h'; consider using 'cwctype' instead
+
+
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: including 'stdalign.h' has no effect in C++; consider removing it
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: including 'stdbool.h' has no effect in C++; consider removing it
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: including 'iso646.h' has no effect in C++; consider removing it
 
 // CHECK-FIXES: #include <cassert>
-// CHECK-FIXES: #include <ccomplex>
+// CHECK-FIXES: #include <complex>
 // CHECK-FIXES: #include <cctype>
 // CHECK-FIXES: #include <cerrno>
 // CHECK-FIXES: #include <cfloat>
-// CHECK-FIXES: #include <cinttypes>
-// CHECK-FIXES: #include <ciso646>
 // CHECK-FIXES: #include <climits>
 // CHECK-FIXES: #include <clocale>
 // CHECK-FIXES: #include <cmath>
@@ -65,7 +67,6 @@
 // CHECK-FIXES: #include <csignal>
 // CHECK-FIXES: #include <cstdarg>
 // CHECK-FIXES: #include <cstddef>
-// CHECK-FIXES: #include <cstdint>
 // CHECK-FIXES: #include <cstdio>
 // CHECK-FIXES: #include <cstdlib>
 // CHECK-FIXES: #include <cstring>
@@ -78,8 +79,6 @@
 #include "ctype.h"
 #include "errno.h"
 #include "float.h"
-#include "inttypes.h"
-#include "iso646.h"
 #include "limits.h"
 #include "locale.h"
 #include "math.h"
@@ -87,7 +86,6 @@
 #include "signal.h"
 #include "stdarg.h"
 #include "stddef.h"
-#include "stdint.h"
 #include "stdio.h"
 #include "stdlib.h"
 #include "string.h"
@@ -95,42 +93,47 @@
 #include "wchar.h"
 #include "wctype.h"
 
-// Headers deprecated since C++11; expect no diagnostics
-#include "fenv.h"
+// Headers that have no effect in C++; remove them
 #include "stdalign.h"
 #include "stdbool.h"
+#include "iso646.h"
+
+// Headers deprecated since C++11; expect no diagnostics
+#include "fenv.h"
+#include "inttypes.h"
+#include "stdint.h"
 #include "tgmath.h"
 #include "uchar.h"
 
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'assert.h'; consider using 'cassert' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'complex.h'; consider using 'ccomplex' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'ctype.h'; consider using 'cctype' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'errno.h'; consider using 'cerrno' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'float.h'; consider using 'cfloat' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'inttypes.h'; consider using 'cinttypes' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'iso646.h'; consider using 'ciso646' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'limits.h'; consider using 'climits' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'locale.h'; consider using 'clocale' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'math.h'; consider using 'cmath' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'setjmp.h'; consider using 'csetjmp' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'signal.h'; consider using 'csignal' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'stdarg.h'; consider using 'cstdarg' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'stddef.h'; consider using 'cstddef' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'stdint.h'; consider using 'cstdint' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'stdio.h'; consider using 'cstdio' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'stdlib.h'; consider using 'cstdlib' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'string.h'; consider using 'cstring' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'time.h'; consider using 'ctime' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'wchar.h'; consider using 'cwchar' instead
-// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'wctype.h'; consider using 'cwctype' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'assert.h'; consider using 'cassert' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'complex.h'; consider using 'complex' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'ctype.h'; consider using 'cctype' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'errno.h'; consider using 'cerrno' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'float.h'; consider using 'cfloat' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'limits.h'; consider using 'climits' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'locale.h'; consider using 'clocale' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'math.h'; consider using 'cmath' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'setjmp.h'; consider using 'csetjmp' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'signal.h'; consider using 'csignal' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'stdarg.h'; consider using 'cstdarg' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'stddef.h'; consider using 'cstddef' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'stdio.h'; consider using 'cstdio' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'stdlib.h'; consider using 'cstdlib' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'string.h'; consider using 'cstring' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'time.h'; consider using 'ctime' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'wchar.h'; consider using 'cwchar' instead
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: inclusion of deprecated C++ header 'wctype.h'; consider using 'cwctype' instead
+
+
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: including 'stdalign.h' has no effect in C++; consider removing it
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: including 'stdbool.h' has no effect in C++; consider removing it
+// CHECK-MESSAGES: :[[@LINE-31]]:10: warning: including 'iso646.h' has no effect in C++; consider removing it
 
 // CHECK-FIXES: #include <cassert>
-// CHECK-FIXES: #include <ccomplex>
+// CHECK-FIXES: #include <complex>
 // CHECK-FIXES: #include <cctype>
 // CHECK-FIXES: #include <cerrno>
 // CHECK-FIXES: #include <cfloat>
-// CHECK-FIXES: #include <cinttypes>
-// CHECK-FIXES: #include <ciso646>
 // CHECK-FIXES: #include <climits>
 // CHECK-FIXES: #include <clocale>
 // CHECK-FIXES: #include <cmath>
@@ -138,7 +141,6 @@
 // CHECK-FIXES: #include <csignal>
 // CHECK-FIXES: #include <cstdarg>
 // CHECK-FIXES: #include <cstddef>
-// CHECK-FIXES: #include <cstdint>
 // CHECK-FIXES: #include <cstdio>
 // CHECK-FIXES: #include <cstdlib>
 // CHECK-FIXES: #include <cstring>
Index: test/clang-tidy/modernize-deprecated-headers-cxx11.cpp
===================================================================
--- test/clang-tidy/modernize-deprecated-headers-cxx11.cpp
+++ test/clang-tidy/modernize-deprecated-headers-cxx11.cpp
@@ -7,15 +7,12 @@
 #include <fenv.h>
 #include <float.h>
 #include <inttypes.h>
-#include <iso646.h>
 #include <limits.h>
 #include <locale.h>
 #include <math.h>
 #include <setjmp.h>
 #include <signal.h>
-#include <stdalign.h>
 #include <stdarg.h>
-#include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
@@ -27,49 +24,53 @@
 #include <wchar.h>
 #include <wctype.h>
 
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'assert.h'; consider using 'cassert' instead [modernize-deprecated-headers]
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'complex.h'; consider using 'ccomplex' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'ctype.h'; consider using 'cctype' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'errno.h'; consider using 'cerrno' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'fenv.h'; consider using 'cfenv' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'float.h'; consider using 'cfloat' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'inttypes.h'; consider using 'cinttypes' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'iso646.h'; consider using 'ciso646' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'limits.h'; consider using 'climits' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'locale.h'; consider using 'clocale' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'math.h'; consider using 'cmath' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'setjmp.h'; consider using 'csetjmp' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'signal.h'; consider using 'csignal' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'stdalign.h'; consider using 'cstdalign' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'stdarg.h'; consider using 'cstdarg' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'stdbool.h'; consider using 'cstdbool' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'stddef.h'; consider using 'cstddef' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'stdint.h'; consider using 'cstdint' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'stdio.h'; consider using 'cstdio' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'stdlib.h'; consider using 'cstdlib' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'string.h'; consider using 'cstring' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'tgmath.h'; consider using 'ctgmath' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'time.h'; consider using 'ctime' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'uchar.h'; consider using 'cuchar' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'wchar.h'; consider using 'cwchar' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'wctype.h'; consider using 'cwctype' instead
+// Headers that have no effect in C++; remove them
+#include <stdalign.h>
+#include <stdbool.h>
+#include <iso646.h>
+
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'assert.h'; consider using 'cassert' instead [modernize-deprecated-headers]
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'complex.h'; consider using 'complex' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'ctype.h'; consider using 'cctype' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'errno.h'; consider using 'cerrno' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'fenv.h'; consider using 'cfenv' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'float.h'; consider using 'cfloat' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'inttypes.h'; consider using 'cinttypes' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'limits.h'; consider using 'climits' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'locale.h'; consider using 'clocale' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'math.h'; consider using 'cmath' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'setjmp.h'; consider using 'csetjmp' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'signal.h'; consider using 'csignal' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'stdarg.h'; consider using 'cstdarg' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'stddef.h'; consider using 'cstddef' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'stdint.h'; consider using 'cstdint' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'stdio.h'; consider using 'cstdio' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'stdlib.h'; consider using 'cstdlib' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'string.h'; consider using 'cstring' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'tgmath.h'; consider using 'ctgmath' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'time.h'; consider using 'ctime' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'uchar.h'; consider using 'cuchar' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'wchar.h'; consider using 'cwchar' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'wctype.h'; consider using 'cwctype' instead
+
+
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: including 'stdalign.h' has no effect in C++; consider removing it
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: including 'stdbool.h' has no effect in C++; consider removing it
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: including 'iso646.h' has no effect in C++; consider removing it
 
 // CHECK-FIXES: #include <cassert>
-// CHECK-FIXES: #include <ccomplex>
+// CHECK-FIXES: #include <complex>
 // CHECK-FIXES: #include <cctype>
 // CHECK-FIXES: #include <cerrno>
 // CHECK-FIXES: #include <cfenv>
 // CHECK-FIXES: #include <cfloat>
 // CHECK-FIXES: #include <cinttypes>
-// CHECK-FIXES: #include <ciso646>
 // CHECK-FIXES: #include <climits>
 // CHECK-FIXES: #include <clocale>
 // CHECK-FIXES: #include <cmath>
 // CHECK-FIXES: #include <csetjmp>
 // CHECK-FIXES: #include <csignal>
-// CHECK-FIXES: #include <cstdalign>
 // CHECK-FIXES: #include <cstdarg>
-// CHECK-FIXES: #include <cstdbool>
 // CHECK-FIXES: #include <cstddef>
 // CHECK-FIXES: #include <cstdint>
 // CHECK-FIXES: #include <cstdio>
@@ -88,15 +89,12 @@
 #include "fenv.h"
 #include "float.h"
 #include "inttypes.h"
-#include "iso646.h"
 #include "limits.h"
 #include "locale.h"
 #include "math.h"
 #include "setjmp.h"
 #include "signal.h"
-#include "stdalign.h"
 #include "stdarg.h"
-#include "stdbool.h"
 #include "stddef.h"
 #include "stdint.h"
 #include "stdio.h"
@@ -108,49 +106,53 @@
 #include "wchar.h"
 #include "wctype.h"
 
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'assert.h'; consider using 'cassert' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'complex.h'; consider using 'ccomplex' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'ctype.h'; consider using 'cctype' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'errno.h'; consider using 'cerrno' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'fenv.h'; consider using 'cfenv' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'float.h'; consider using 'cfloat' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'inttypes.h'; consider using 'cinttypes' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'iso646.h'; consider using 'ciso646' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'limits.h'; consider using 'climits' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'locale.h'; consider using 'clocale' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'math.h'; consider using 'cmath' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'setjmp.h'; consider using 'csetjmp' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'signal.h'; consider using 'csignal' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'stdalign.h'; consider using 'cstdalign' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'stdarg.h'; consider using 'cstdarg' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'stdbool.h'; consider using 'cstdbool' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'stddef.h'; consider using 'cstddef' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'stdint.h'; consider using 'cstdint' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'stdio.h'; consider using 'cstdio' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'stdlib.h'; consider using 'cstdlib' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'string.h'; consider using 'cstring' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'tgmath.h'; consider using 'ctgmath' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'time.h'; consider using 'ctime' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'uchar.h'; consider using 'cuchar' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'wchar.h'; consider using 'cwchar' instead
-// CHECK-MESSAGES: :[[@LINE-27]]:10: warning: inclusion of deprecated C++ header 'wctype.h'; consider using 'cwctype' instead
+// Headers that have no effect in C++; remove them
+#include "stdalign.h"
+#include "stdbool.h"
+#include "iso646.h"
+
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'assert.h'; consider using 'cassert' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'complex.h'; consider using 'complex' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'ctype.h'; consider using 'cctype' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'errno.h'; consider using 'cerrno' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'fenv.h'; consider using 'cfenv' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'float.h'; consider using 'cfloat' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'inttypes.h'; consider using 'cinttypes' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'limits.h'; consider using 'climits' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'locale.h'; consider using 'clocale' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'math.h'; consider using 'cmath' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'setjmp.h'; consider using 'csetjmp' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'signal.h'; consider using 'csignal' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'stdarg.h'; consider using 'cstdarg' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'stddef.h'; consider using 'cstddef' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'stdint.h'; consider using 'cstdint' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'stdio.h'; consider using 'cstdio' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'stdlib.h'; consider using 'cstdlib' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'string.h'; consider using 'cstring' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'tgmath.h'; consider using 'ctgmath' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'time.h'; consider using 'ctime' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'uchar.h'; consider using 'cuchar' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'wchar.h'; consider using 'cwchar' instead
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: inclusion of deprecated C++ header 'wctype.h'; consider using 'cwctype' instead
+
+
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: including 'stdalign.h' has no effect in C++; consider removing it
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: including 'stdbool.h' has no effect in C++; consider removing it
+// CHECK-MESSAGES: :[[@LINE-29]]:10: warning: including 'iso646.h' has no effect in C++; consider removing it
 
 // CHECK-FIXES: #include <cassert>
-// CHECK-FIXES: #include <ccomplex>
+// CHECK-FIXES: #include <complex>
 // CHECK-FIXES: #include <cctype>
 // CHECK-FIXES: #include <cerrno>
 // CHECK-FIXES: #include <cfenv>
 // CHECK-FIXES: #include <cfloat>
 // CHECK-FIXES: #include <cinttypes>
-// CHECK-FIXES: #include <ciso646>
 // CHECK-FIXES: #include <climits>
 // CHECK-FIXES: #include <clocale>
 // CHECK-FIXES: #include <cmath>
 // CHECK-FIXES: #include <csetjmp>
 // CHECK-FIXES: #include <csignal>
-// CHECK-FIXES: #include <cstdalign>
 // CHECK-FIXES: #include <cstdarg>
-// CHECK-FIXES: #include <cstdbool>
 // CHECK-FIXES: #include <cstddef>
 // CHECK-FIXES: #include <cstdint>
 // CHECK-FIXES: #include <cstdio>