Change (void) casts to TEST_IGNORE_NODISCARD, as requested by Eric. Reviewed as https://reviews.llvm.org/D40065

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@318804 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/algorithms/alg.nonmodifying/alg.search/search_n_pred.pass.cpp

@@ -142,7 +142,7 @@ test()
     count_equal::count = 0;
 
     // Check that we properly convert the size argument to an integral.
-    (void)std::search_n(Iter(ic), Iter(ic+sc), UserDefinedIntegral<unsigned>(4), 0, count_equal());
+    TEST_IGNORE_NODISCARD std::search_n(Iter(ic), Iter(ic+sc), UserDefinedIntegral<unsigned>(4), 0, count_equal());
     count_equal::count = 0;
 }
 

test/std/containers/associative/map/map.access/at.pass.cpp

@@ -46,7 +46,7 @@ int main()
 #ifndef TEST_HAS_NO_EXCEPTIONS
         try
         {
-            (void)m.at(6);
+            TEST_IGNORE_NODISCARD m.at(6);
             assert(false);
         }
         catch (std::out_of_range&)
@@ -79,7 +79,7 @@ int main()
 #ifndef TEST_HAS_NO_EXCEPTIONS
         try
         {
-            (void)m.at(6);
+            TEST_IGNORE_NODISCARD m.at(6);
             assert(false);
         }
         catch (std::out_of_range&)
@@ -115,7 +115,7 @@ int main()
 #ifndef TEST_HAS_NO_EXCEPTIONS
         try
         {
-            (void)m.at(6);
+            TEST_IGNORE_NODISCARD m.at(6);
             assert(false);
         }
         catch (std::out_of_range&)
@@ -148,7 +148,7 @@ int main()
 #ifndef TEST_HAS_NO_EXCEPTIONS
         try
         {
-            (void)m.at(6);
+            TEST_IGNORE_NODISCARD m.at(6);
             assert(false);
         }
         catch (std::out_of_range&)

test/std/containers/associative/map/map.ops/count1.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::map<int, double, transparent_less_no_type> M;
 
-    (void)M().count(C2Int{5});
+    TEST_IGNORE_NODISCARD M().count(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/map/map.ops/count2.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::map<int, double, transparent_less_private> M;
 
-    (void)M().count(C2Int{5});
+    TEST_IGNORE_NODISCARD M().count(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/map/map.ops/count3.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::map<int, double, transparent_less_not_a_type> M;
 
-    (void)M().count(C2Int{5});
+    TEST_IGNORE_NODISCARD M().count(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/map/map.ops/equal_range1.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::map<int, double, transparent_less_no_type> M;
 
-    (void)M().equal_range(C2Int{5});
+    TEST_IGNORE_NODISCARD M().equal_range(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/map/map.ops/equal_range2.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::map<int, double, transparent_less_private> M;
 
-    (void)M().equal_range(C2Int{5});
+    TEST_IGNORE_NODISCARD M().equal_range(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/map/map.ops/equal_range3.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::map<int, double, transparent_less_not_a_type> M;
 
-    (void)M().equal_range(C2Int{5});
+    TEST_IGNORE_NODISCARD M().equal_range(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/map/map.ops/find1.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::map<int, double, transparent_less_no_type> M;
 
-    (void)M().find(C2Int{5});
+    TEST_IGNORE_NODISCARD M().find(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/map/map.ops/find2.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::map<int, double, transparent_less_private> M;
 
-    (void)M().find(C2Int{5});
+    TEST_IGNORE_NODISCARD M().find(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/map/map.ops/find3.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::map<int, double, transparent_less_not_a_type> M;
 
-    (void)M().find(C2Int{5});
+    TEST_IGNORE_NODISCARD M().find(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/map/map.ops/lower_bound1.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::map<int, double, transparent_less_no_type> M;
 
-    (void)M().lower_bound(C2Int{5});
+    TEST_IGNORE_NODISCARD M().lower_bound(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/map/map.ops/lower_bound2.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::map<int, double, transparent_less_private> M;
 
-    (void)M().lower_bound(C2Int{5});
+    TEST_IGNORE_NODISCARD M().lower_bound(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/map/map.ops/lower_bound3.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::map<int, double, transparent_less_not_a_type> M;
 
-    (void)M().lower_bound(C2Int{5});
+    TEST_IGNORE_NODISCARD M().lower_bound(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/map/map.ops/upper_bound1.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::map<int, double, transparent_less_no_type> M;
 
-    (void)M().upper_bound(C2Int{5});
+    TEST_IGNORE_NODISCARD M().upper_bound(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/map/map.ops/upper_bound2.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::map<int, double, transparent_less_private> M;
 
-    (void)M().upper_bound(C2Int{5});
+    TEST_IGNORE_NODISCARD M().upper_bound(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/map/map.ops/upper_bound3.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::map<int, double, transparent_less_not_a_type> M;
 
-    (void)M().upper_bound(C2Int{5});
+    TEST_IGNORE_NODISCARD M().upper_bound(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/multimap/multimap.ops/count1.fail.cpp

@@ -33,6 +33,6 @@ int main()
 {
     typedef std::multimap<int, double, transparent_less_no_type> M;
 
-    (void)M().count(C2Int{5});
+    TEST_IGNORE_NODISCARD M().count(C2Int{5});
 }
 #endif

test/std/containers/associative/multimap/multimap.ops/count2.fail.cpp

@@ -33,6 +33,6 @@ int main()
 {
     typedef std::multimap<int, double, transparent_less_private> M;
 
-    (void)M().count(C2Int{5});
+    TEST_IGNORE_NODISCARD M().count(C2Int{5});
 }
 #endif

test/std/containers/associative/multimap/multimap.ops/count3.fail.cpp

@@ -33,6 +33,6 @@ int main()
 {
     typedef std::multimap<int, double, transparent_less_not_a_type> M;
 
-    (void)M().count(C2Int{5});
+    TEST_IGNORE_NODISCARD M().count(C2Int{5});
 }
 #endif

test/std/containers/associative/multimap/multimap.ops/equal_range1.fail.cpp

@@ -33,6 +33,6 @@ int main()
 {
     typedef std::multimap<int, double, transparent_less_no_type> M;
 
-    (void)M().equal_range(C2Int{5});
+    TEST_IGNORE_NODISCARD M().equal_range(C2Int{5});
 }
 #endif

test/std/containers/associative/multimap/multimap.ops/equal_range2.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::multimap<int, double, transparent_less_private> M;
 
-    (void)M().equal_range(C2Int{5});
+    TEST_IGNORE_NODISCARD M().equal_range(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/multimap/multimap.ops/equal_range3.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::multimap<int, double, transparent_less_not_a_type> M;
 
-    (void)M().equal_range(C2Int{5});
+    TEST_IGNORE_NODISCARD M().equal_range(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/multimap/multimap.ops/find1.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::multimap<int, double, transparent_less_no_type> M;
 
-    (void)M().find(C2Int{5});
+    TEST_IGNORE_NODISCARD M().find(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/multimap/multimap.ops/find2.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::multimap<int, double, transparent_less_private> M;
 
-    (void)M().find(C2Int{5});
+    TEST_IGNORE_NODISCARD M().find(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/multimap/multimap.ops/find3.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::multimap<int, double, transparent_less_not_a_type> M;
 
-    (void)M().find(C2Int{5});
+    TEST_IGNORE_NODISCARD M().find(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/multimap/multimap.ops/lower_bound1.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::multimap<int, double, transparent_less_no_type> M;
 
-    (void)M().lower_bound(C2Int{5});
+    TEST_IGNORE_NODISCARD M().lower_bound(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/multimap/multimap.ops/lower_bound2.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::multimap<int, double, transparent_less_private> M;
 
-    (void)M().lower_bound(C2Int{5});
+    TEST_IGNORE_NODISCARD M().lower_bound(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/multimap/multimap.ops/lower_bound3.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::multimap<int, double, transparent_less_not_a_type> M;
 
-    (void)M().lower_bound(C2Int{5});
+    TEST_IGNORE_NODISCARD M().lower_bound(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/multimap/multimap.ops/upper_bound1.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::multimap<int, double, transparent_less_no_type> M;
 
-    (void)M().upper_bound(C2Int{5});
+    TEST_IGNORE_NODISCARD M().upper_bound(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/multimap/multimap.ops/upper_bound2.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::multimap<int, double, transparent_less_private> M;
 
-    (void)M().upper_bound(C2Int{5});
+    TEST_IGNORE_NODISCARD M().upper_bound(C2Int{5});
     }
 }
 #endif

test/std/containers/associative/multimap/multimap.ops/upper_bound3.fail.cpp

@@ -34,7 +34,7 @@ int main()
     {
     typedef std::multimap<int, double, transparent_less_not_a_type> M;
 
-    (void)M().upper_bound(C2Int{5});
+    TEST_IGNORE_NODISCARD M().upper_bound(C2Int{5});
     }
 }
 #endif

test/std/containers/sequences/array/at.pass.cpp

@@ -50,7 +50,7 @@ int main()
 #ifndef TEST_HAS_NO_EXCEPTIONS
         try
         {
-            (void) c.at(3);
+            TEST_IGNORE_NODISCARD  c.at(3);
             assert(false);
         }
         catch (const std::out_of_range &) {}
@@ -69,7 +69,7 @@ int main()
 #ifndef TEST_HAS_NO_EXCEPTIONS
         try
         {
-            (void) c.at(3);
+            TEST_IGNORE_NODISCARD  c.at(3);
             assert(false);
         }
         catch (const std::out_of_range &) {}

test/std/containers/unord/unord.map/unord.map.elem/at.pass.cpp

@@ -72,7 +72,7 @@ int main()
 #ifndef TEST_HAS_NO_EXCEPTIONS
         try
         {
-            (void)c.at(11);
+            TEST_IGNORE_NODISCARD c.at(11);
             assert(false);
         }
         catch (std::out_of_range&)
@@ -130,7 +130,7 @@ int main()
 #ifndef TEST_HAS_NO_EXCEPTIONS
         try
         {
-            (void)c.at(11);
+            TEST_IGNORE_NODISCARD c.at(11);
             assert(false);
         }
         catch (std::out_of_range&)

test/std/diagnostics/syserr/syserr.errcode/syserr.errcode.overview/types.pass.cpp

@@ -13,11 +13,12 @@
 // Make sure that the error_code bits of <system_error> are self-contained.
 
 #include <system_error>
+#include "test_macros.h"
 
 int main()
 {
     std::error_code x;
-    (void) x.category();   // returns a std::error_category &
-    (void) x.default_error_condition(); // std::error_condition
-    (void) x.message();    // returns a std::string
+    TEST_IGNORE_NODISCARD  x.category();   // returns a std::error_category &
+    TEST_IGNORE_NODISCARD  x.default_error_condition(); // std::error_condition
+    TEST_IGNORE_NODISCARD  x.message();    // returns a std::string
 }

test/std/diagnostics/syserr/syserr.errcondition/syserr.errcondition.overview/types.pass.cpp

@@ -13,10 +13,11 @@
 // Make sure that the error_condition bits of <system_error> are self-contained.
 
 #include <system_error>
+#include "test_macros.h"
 
 int main()
 {
     std::error_condition x = std::errc(0);
-    (void) x.category();   // returns a std::error_condition &
-    (void) x.message();    // returns a std::string
+    TEST_IGNORE_NODISCARD  x.category();   // returns a std::error_condition &
+    TEST_IGNORE_NODISCARD  x.message();    // returns a std::string
 }

test/std/iterators/iterator.range/begin-end.fail.cpp

@@ -43,9 +43,9 @@ namespace Foo {
 
 int main(){
 // Bug #28927 - shouldn't find these via ADL
-    (void) std::cbegin (Foo::FakeContainer());
-    (void) std::cend   (Foo::FakeContainer());
-    (void) std::crbegin(Foo::FakeContainer());
-    (void) std::crend  (Foo::FakeContainer());
+    TEST_IGNORE_NODISCARD  std::cbegin (Foo::FakeContainer());
+    TEST_IGNORE_NODISCARD  std::cend   (Foo::FakeContainer());
+    TEST_IGNORE_NODISCARD  std::crbegin(Foo::FakeContainer());
+    TEST_IGNORE_NODISCARD  std::crend  (Foo::FakeContainer());
 }
 #endif

test/std/iterators/iterators.general/gcc_workaround.pass.cpp

@@ -10,11 +10,12 @@
 // Tests workaround for  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64816.
 
 #include <string>
+#include "test_macros.h"
 
-void f(const std::string &s) { (void)s.begin(); }
+void f(const std::string &s) { TEST_IGNORE_NODISCARD s.begin(); }
 
 #include <vector>
 
-void AppendTo(const std::vector<char> &v) { (void)v.begin(); }
+void AppendTo(const std::vector<char> &v) { TEST_IGNORE_NODISCARD v.begin(); }
 
 int main() {}

test/std/iterators/predef.iterators/insert.iterators/insert.iterator/types.pass.cpp

@@ -29,6 +29,7 @@
 #include <iterator>
 #include <type_traits>
 #include <vector>
+#include "test_macros.h"
 
 template <class C>
 struct find_members
@@ -38,7 +39,7 @@ struct find_members
     void test()
     {
         this->container = 0;
-        (void)(this->iter == this->iter);
+        TEST_IGNORE_NODISCARD (this->iter == this->iter);
     }
 };
 

test/std/iterators/predef.iterators/move.iterators/move.iter.ops/move.iter.nonmember/make_move_iterator.pass.cpp

@@ -43,8 +43,8 @@ int main()
     }
     {
     int a[] = {1,2,3,4};
-    (void)std::make_move_iterator(a+4);
-    (void)std::make_move_iterator(a); // test for LWG issue 2061
+    TEST_IGNORE_NODISCARD std::make_move_iterator(a+4);
+    TEST_IGNORE_NODISCARD std::make_move_iterator(a); // test for LWG issue 2061
     }
 
 #if TEST_STD_VER > 14

test/std/numerics/numeric.ops/numeric.ops.lcm/lcm.pass.cpp

@@ -19,6 +19,7 @@
 #include <cstdint>
 #include <cstdlib>
 #include <type_traits>
+#include "test_macros.h"
 
 constexpr struct {
   int x;
@@ -137,7 +138,7 @@ int main()
 //  LWG#2837
     {
     auto res1 = std::lcm(static_cast<std::int64_t>(1234), INT32_MIN);
-    (void)std::lcm(INT_MIN, 2UL);   // this used to trigger UBSAN
+    TEST_IGNORE_NODISCARD std::lcm(INT_MIN, 2UL);   // this used to trigger UBSAN
     static_assert(std::is_same_v<decltype(res1), std::int64_t>, "");
     assert(res1 == 1324997410816LL);
     }

test/std/re/re.alg/re.alg.search/grep.pass.cpp

@@ -33,7 +33,7 @@ extern "C" void LLVMFuzzerTestOneInput(const char *data)
             std::regex::flag_type flag = std::regex_constants::grep;
             std::string s((const char *)data, size);
             std::regex re(s, flag);
-            (void)std::regex_match(s, re);
+            TEST_IGNORE_NODISCARD std::regex_match(s, re);
         }
         catch (std::regex_error &) {}
     }

test/std/re/re.grammar/excessive_brace_count.pass.cpp

@@ -20,7 +20,7 @@ int main() {
   for (std::regex_constants::syntax_option_type op :
        {std::regex::basic, std::regex::grep}) {
     try {
-      (void)std::regex("a\\{100000000000000000\\}", op);
+      TEST_IGNORE_NODISCARD std::regex("a\\{100000000000000000\\}", op);
       assert(false);
     } catch (const std::regex_error &e) {
       assert(e.code() == std::regex_constants::error_badbrace);
@@ -30,7 +30,7 @@ int main() {
        {std::regex::ECMAScript, std::regex::extended, std::regex::egrep,
         std::regex::awk}) {
     try {
-      (void)std::regex("a{100000000000000000}", op);
+      TEST_IGNORE_NODISCARD std::regex("a{100000000000000000}", op);
       assert(false);
     } catch (const std::regex_error &e) {
       assert(e.code() == std::regex_constants::error_badbrace);

test/std/strings/basic.string/string.access/at.pass.cpp

@@ -35,7 +35,7 @@ test(S s, typename S::size_type pos)
     {
         try
         {
-            (void)s.at(pos);
+            TEST_IGNORE_NODISCARD s.at(pos);
             assert(false);
         }
         catch (std::out_of_range&)
@@ -44,7 +44,7 @@ test(S s, typename S::size_type pos)
         }
         try
         {
-            (void)cs.at(pos);
+            TEST_IGNORE_NODISCARD cs.at(pos);
             assert(false);
         }
         catch (std::out_of_range&)

test/std/strings/basic.string/string.ops/string_compare/size_size_T_size_size.pass.cpp

@@ -45,7 +45,7 @@ test(const S& s, typename S::size_type pos1, typename S::size_type n1,
     {
         try
         {
-            (void)s.compare(pos1, n1, sv, pos2, n2);
+            TEST_IGNORE_NODISCARD s.compare(pos1, n1, sv, pos2, n2);
             assert(false);
         }
         catch (const std::out_of_range&)
@@ -69,7 +69,7 @@ test_npos(const S& s, typename S::size_type pos1, typename S::size_type n1,
     {
         try
         {
-            (void)s.compare(pos1, n1, sv, pos2);
+            TEST_IGNORE_NODISCARD s.compare(pos1, n1, sv, pos2);
             assert(false);
         }
         catch (const std::out_of_range&)

test/std/strings/basic.string/string.ops/string_compare/size_size_pointer.pass.cpp

@@ -40,7 +40,7 @@ test(const S& s, typename S::size_type pos1, typename S::size_type n1,
     {
         try
         {
-            (void)s.compare(pos1, n1, str);
+            TEST_IGNORE_NODISCARD s.compare(pos1, n1, str);
             assert(false);
         }
         catch (std::out_of_range&)

test/std/strings/basic.string/string.ops/string_compare/size_size_pointer_size.pass.cpp

@@ -40,7 +40,7 @@ test(const S& s, typename S::size_type pos, typename S::size_type n1,
     {
         try
         {
-            (void)s.compare(pos, n1, str, n2);
+            TEST_IGNORE_NODISCARD s.compare(pos, n1, str, n2);
             assert(false);
         }
         catch (std::out_of_range&)

test/std/strings/basic.string/string.ops/string_compare/size_size_string.pass.cpp

@@ -40,7 +40,7 @@ test(const S& s, typename S::size_type pos1, typename S::size_type n1,
     {
         try
         {
-            (void)s.compare(pos1, n1, str);
+            TEST_IGNORE_NODISCARD s.compare(pos1, n1, str);
             assert(false);
         }
         catch (std::out_of_range&)

test/std/strings/basic.string/string.ops/string_compare/size_size_string_size_size.pass.cpp

@@ -42,7 +42,7 @@ test(const S& s,   typename S::size_type pos1, typename S::size_type n1,
     {
         try
         {
-            (void)s.compare(pos1, n1, str, pos2, n2);
+            TEST_IGNORE_NODISCARD s.compare(pos1, n1, str, pos2, n2);
             assert(false);
         }
         catch (const std::out_of_range&)
@@ -65,7 +65,7 @@ test_npos(const S& s,   typename S::size_type pos1, typename S::size_type n1,
     {
         try
         {
-            (void)s.compare(pos1, n1, str, pos2);
+            TEST_IGNORE_NODISCARD s.compare(pos1, n1, str, pos2);
             assert(false);
         }
         catch (const std::out_of_range&)

test/std/strings/basic.string/string.ops/string_compare/size_size_string_view.pass.cpp

@@ -40,7 +40,7 @@ test(const S& s, typename S::size_type pos1, typename S::size_type n1,
     {
         try
         {
-            (void)s.compare(pos1, n1, sv);
+            TEST_IGNORE_NODISCARD s.compare(pos1, n1, sv);
             assert(false);
         }
         catch (std::out_of_range&)

test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/try_lock.pass.cpp

@@ -44,7 +44,7 @@ int main()
 #ifndef TEST_HAS_NO_EXCEPTIONS
     try
     {
-        (void)lk.try_lock();
+        TEST_IGNORE_NODISCARD lk.try_lock();
         assert(false);
     }
     catch (std::system_error& e)
@@ -60,7 +60,7 @@ int main()
 #ifndef TEST_HAS_NO_EXCEPTIONS
     try
     {
-        (void)lk.try_lock();
+        TEST_IGNORE_NODISCARD lk.try_lock();
         assert(false);
     }
     catch (std::system_error& e)

test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/try_lock_for.pass.cpp

@@ -49,7 +49,7 @@ int main()
 #ifndef TEST_HAS_NO_EXCEPTIONS
     try
     {
-        (void)lk.try_lock_for(ms(5));
+        TEST_IGNORE_NODISCARD lk.try_lock_for(ms(5));
         assert(false);
     }
     catch (std::system_error& e)
@@ -65,7 +65,7 @@ int main()
 #ifndef TEST_HAS_NO_EXCEPTIONS
     try
     {
-        (void)lk.try_lock_for(ms(5));
+        TEST_IGNORE_NODISCARD lk.try_lock_for(ms(5));
         assert(false);
     }
     catch (std::system_error& e)

test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/try_lock_until.pass.cpp

@@ -49,7 +49,7 @@ int main()
 #ifndef TEST_HAS_NO_EXCEPTIONS
     try
     {
-        (void)lk.try_lock_until(Clock::now());
+        TEST_IGNORE_NODISCARD lk.try_lock_until(Clock::now());
         assert(false);
     }
     catch (std::system_error& e)
@@ -65,7 +65,7 @@ int main()
 #ifndef TEST_HAS_NO_EXCEPTIONS
     try
     {
-        (void)lk.try_lock_until(Clock::now());
+        TEST_IGNORE_NODISCARD lk.try_lock_until(Clock::now());
         assert(false);
     }
     catch (std::system_error& e)

test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.locking/try_lock.pass.cpp

@@ -43,7 +43,7 @@ int main()
 #ifndef TEST_HAS_NO_EXCEPTIONS
     try
     {
-        (void)lk.try_lock();
+        TEST_IGNORE_NODISCARD lk.try_lock();
         assert(false);
     }
     catch (std::system_error& e)
@@ -59,7 +59,7 @@ int main()
 #ifndef TEST_HAS_NO_EXCEPTIONS
     try
     {
-        (void)lk.try_lock();
+        TEST_IGNORE_NODISCARD lk.try_lock();
         assert(false);
     }
     catch (std::system_error& e)

test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.locking/try_lock_for.pass.cpp

@@ -48,7 +48,7 @@ int main()
 #ifndef TEST_HAS_NO_EXCEPTIONS
     try
     {
-        (void)lk.try_lock_for(ms(5));
+        TEST_IGNORE_NODISCARD lk.try_lock_for(ms(5));
         assert(false);
     }
     catch (std::system_error& e)
@@ -64,7 +64,7 @@ int main()
 #ifndef TEST_HAS_NO_EXCEPTIONS
     try
     {
-        (void)lk.try_lock_for(ms(5));
+        TEST_IGNORE_NODISCARD lk.try_lock_for(ms(5));
         assert(false);
     }
     catch (std::system_error& e)

test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.locking/try_lock_until.pass.cpp

@@ -48,7 +48,7 @@ int main()
 #ifndef TEST_HAS_NO_EXCEPTIONS
     try
     {
-        (void)lk.try_lock_until(Clock::now());
+        TEST_IGNORE_NODISCARD lk.try_lock_until(Clock::now());
         assert(false);
     }
     catch (std::system_error& e)
@@ -64,7 +64,7 @@ int main()
 #ifndef TEST_HAS_NO_EXCEPTIONS
     try
     {
-        (void)lk.try_lock_until(Clock::now());
+        TEST_IGNORE_NODISCARD lk.try_lock_until(Clock::now());
         assert(false);
     }
     catch (std::system_error& e)

test/std/utilities/any/any.nonmembers/any.cast/any_cast_reference.pass.cpp

@@ -80,7 +80,7 @@ void checkThrows(any& a)
 {
 #if !defined(TEST_HAS_NO_EXCEPTIONS)
     try {
-        (void)any_cast<Type>(a);
+        TEST_IGNORE_NODISCARD any_cast<Type>(a);
         assert(false);
     } catch (bad_any_cast const &) {
             // do nothing
@@ -89,7 +89,7 @@ void checkThrows(any& a)
     }
 
     try {
-        (void)any_cast<ConstT>(static_cast<any const&>(a));
+        TEST_IGNORE_NODISCARD any_cast<ConstT>(static_cast<any const&>(a));
         assert(false);
     } catch (bad_any_cast const &) {
             // do nothing
@@ -103,7 +103,7 @@ void checkThrows(any& a)
             typename std::remove_reference<Type>::type&&,
             Type
         >::type;
-        (void)any_cast<RefType>(static_cast<any&&>(a));
+        TEST_IGNORE_NODISCARD any_cast<RefType>(static_cast<any&&>(a));
         assert(false);
     } catch (bad_any_cast const &) {
             // do nothing
@@ -111,13 +111,13 @@ void checkThrows(any& a)
         assert(false);
     }
 #else
-    ((void)a);
+    (TEST_IGNORE_NODISCARD a);
 #endif
 }
 
 void test_cast_empty() {
     // None of these operations should allocate.
-    DisableAllocationGuard g; ((void)g);
+    DisableAllocationGuard g; (TEST_IGNORE_NODISCARD g);
     any a;
     checkThrows<int>(a);
 }

test/std/utilities/any/any.nonmembers/make_any.pass.cpp

@@ -115,14 +115,14 @@ void test_make_any_throws()
 {
     {
         try {
-            (void)std::make_any<Type>(101);
+            TEST_IGNORE_NODISCARD std::make_any<Type>(101);
             assert(false);
         } catch (int const&) {
         }
     }
     {
         try {
-            (void)std::make_any<Type>({1, 2, 3}, 101);
+            TEST_IGNORE_NODISCARD std::make_any<Type>({1, 2, 3}, 101);
             assert(false);
         } catch (int const&) {
         }

test/std/utilities/memory/default.allocator/allocator.members/allocate.size.pass.cpp

@@ -23,7 +23,7 @@ void test_max(size_t count)
 {
     std::allocator<T> a;
     try {
-        (void)a.allocate(count);
+        TEST_IGNORE_NODISCARD a.allocate(count);
         assert(false);
     } catch (const std::exception &) {
     }

test/std/utilities/memory/util.smartptr/util.smartptr.enab/enable_shared_from_this.pass.cpp

@@ -134,7 +134,7 @@ int main()
 
 #ifndef TEST_HAS_NO_EXCEPTIONS
         try {
-            (void)ptr->shared_from_this();
+            TEST_IGNORE_NODISCARD ptr->shared_from_this();
             assert(false);
         } catch (std::bad_weak_ptr const&) {
         } catch (...) { assert(false); }

test/std/utilities/smartptr/unique.ptr/unique.ptr.class/unique.ptr.observers/dereference.runtime.fail.cpp

@@ -19,6 +19,6 @@
 int main() {
   std::unique_ptr<int[]> p(new int(3));
   const std::unique_ptr<int[]>& cp = p;
-  (void)(*p);  // expected-error {{indirection requires pointer operand ('std::unique_ptr<int []>' invalid)}}
-  (void)(*cp); // expected-error {{indirection requires pointer operand ('const std::unique_ptr<int []>' invalid)}}
+  TEST_IGNORE_NODISCARD (*p);  // expected-error {{indirection requires pointer operand ('std::unique_ptr<int []>' invalid)}}
+  TEST_IGNORE_NODISCARD (*cp); // expected-error {{indirection requires pointer operand ('const std::unique_ptr<int []>' invalid)}}
 }

test/std/utilities/tuple/tuple.tuple/tuple.elem/tuple.by.type.fail.cpp

@@ -16,12 +16,12 @@ struct UserType {};
 
 void test_bad_index() {
     std::tuple<long, long, char, std::string, char, UserType, char> t1;
-    (void)std::get<int>(t1); // expected-error@tuple:* {{type not found}}
-    (void)std::get<long>(t1); // expected-note {{requested here}}
-    (void)std::get<char>(t1); // expected-note {{requested here}}
+    TEST_IGNORE_NODISCARD std::get<int>(t1); // expected-error@tuple:* {{type not found}}
+    TEST_IGNORE_NODISCARD std::get<long>(t1); // expected-note {{requested here}}
+    TEST_IGNORE_NODISCARD std::get<char>(t1); // expected-note {{requested here}}
         // expected-error@tuple:* 2 {{type occurs more than once}}
     std::tuple<> t0;
-    (void)std::get<char*>(t0); // expected-node {{requested here}}
+    TEST_IGNORE_NODISCARD std::get<char*>(t0); // expected-node {{requested here}}
         // expected-error@tuple:* 1 {{type not in empty type list}}
 }
 

test/std/utilities/variant/variant.get/get_index.pass.cpp

@@ -259,7 +259,7 @@ void test_throws_for_all_value_categories() {
   auto test = [](auto idx, auto &&v) {
     using Idx = decltype(idx);
     try {
-      (void)std::get<Idx::value>(std::forward<decltype(v)>(v));
+      TEST_IGNORE_NODISCARD std::get<Idx::value>(std::forward<decltype(v)>(v));
     } catch (const std::bad_variant_access &) {
       return true;
     } catch (...) { /* ... */

test/std/utilities/variant/variant.get/get_type.pass.cpp

@@ -259,7 +259,7 @@ void test_throws_for_all_value_categories() {
   auto test = [](auto idx, auto &&v) {
     using Idx = decltype(idx);
     try {
-      (void)std::get<typename Idx::type>(std::forward<decltype(v)>(v));
+      TEST_IGNORE_NODISCARD std::get<typename Idx::type>(std::forward<decltype(v)>(v));
     } catch (const std::bad_variant_access &) {
       return true;
     } catch (...) { /* ... */

test/support/test_macros.h

@@ -189,6 +189,8 @@
 #define LIBCPP_ONLY(...) ((void)0)
 #endif
 
+#define TEST_IGNORE_NODISCARD (void)
+
 namespace test_macros_detail {
 template <class T, class U>
 struct is_same { enum { value = 0};} ;