commit 9b790acc2207d69b4ebc0f4addd34a0aa32ec6cf
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Mon May 24 18:32:22 2021

    libstdc++: Remove unary_function base classes from std::thread tests
    
    std::thread does not care if a function object is adaptable, so there is
    no need to derive from the deprecated std::unary_function class in these
    tests.
    
    Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
    
    libstdc++-v3/ChangeLog:
    
            * testsuite/30_threads/thread/cons/3.cc: Remove derivation from
            std::unary_function.
            * testsuite/30_threads/thread/cons/4.cc: Likewise.
            * testsuite/30_threads/thread/cons/5.cc: Likewise.

diff --git a/libstdc++-v3/testsuite/30_threads/thread/cons/3.cc b/libstdc++-v3/testsuite/30_threads/thread/cons/3.cc
index efdc631d950..6677156b7f2 100644
--- a/libstdc++-v3/testsuite/30_threads/thread/cons/3.cc
+++ b/libstdc++-v3/testsuite/30_threads/thread/cons/3.cc
@@ -21,12 +21,12 @@
 // <http://www.gnu.org/licenses/>.
 
 
-#include <functional> // std::unary_function, std::ref
+#include <functional> // std::ref
 #include <thread>
 #include <system_error>
 #include <testsuite_hooks.h>
 
-struct copyable : public std::unary_function<std::thread::id&, void>
+struct copyable
 {
   copyable() = default;
   ~copyable() = default;
@@ -84,5 +84,4 @@ void test03()
 int main()
 {
   test03();
-  return 0;
 }
diff --git a/libstdc++-v3/testsuite/30_threads/thread/cons/4.cc b/libstdc++-v3/testsuite/30_threads/thread/cons/4.cc
index d74ad9715e3..9508cb45a1b 100644
--- a/libstdc++-v3/testsuite/30_threads/thread/cons/4.cc
+++ b/libstdc++-v3/testsuite/30_threads/thread/cons/4.cc
@@ -21,12 +21,12 @@
 // <http://www.gnu.org/licenses/>.
 
 
-#include <functional> // std::unary_function, std::ref, std::cref
+#include <functional> // std::ref, std::cref
 #include <thread>
 #include <system_error>
 #include <testsuite_hooks.h>
 
-struct noncopyable : std::unary_function<std::thread::id&, void>
+struct noncopyable
 {
   noncopyable() = default;
   ~noncopyable() = default;
diff --git a/libstdc++-v3/testsuite/30_threads/thread/cons/5.cc b/libstdc++-v3/testsuite/30_threads/thread/cons/5.cc
index 74dcd84c058..6d4d6854b30 100644
--- a/libstdc++-v3/testsuite/30_threads/thread/cons/5.cc
+++ b/libstdc++-v3/testsuite/30_threads/thread/cons/5.cc
@@ -21,12 +21,12 @@
 // <http://www.gnu.org/licenses/>.
 
 
-#include <functional> // std::unary_function, std::ref
+#include <functional> // std::ref
 #include <thread>
 #include <system_error>
 #include <testsuite_hooks.h>
 
-struct nonconst : public std::unary_function<std::thread::id&, void>
+struct nonconst
 {
   void operator()(std::thread::id& id)
   {