Make templaitization less awkward

Author: frederick-vs-ja

libcxx/test/std/containers/sequences/vector.bool/vector_bool.pass.cpp

@@ -24,23 +24,20 @@
 
 template <class VB>
 TEST_CONSTEXPR_CXX20 void test() {
-  {
-    typedef VB T;
-    typedef std::hash<T> H;
+  typedef std::hash<VB> H;
 #if TEST_STD_VER <= 14
-    static_assert((std::is_same<H::argument_type, T>::value), "");
-    static_assert((std::is_same<H::result_type, std::size_t>::value), "");
+  static_assert((std::is_same<H::argument_type, VB>::value), "");
+  static_assert((std::is_same<H::result_type, std::size_t>::value), "");
 #endif
-    ASSERT_NOEXCEPT(H()(T()));
-
-    bool ba[] = {true, false, true, true, false};
-    T vb(std::begin(ba), std::end(ba));
-    H h;
-    if (!TEST_IS_CONSTANT_EVALUATED) {
-      const std::size_t hash_value = h(vb);
-      assert(h(vb) == hash_value);
-      LIBCPP_ASSERT(hash_value != 0);
-    }
+  ASSERT_NOEXCEPT(H()(VB()));
+
+  bool ba[] = {true, false, true, true, false};
+  VB vb(std::begin(ba), std::end(ba));
+  H h;
+  if (!TEST_IS_CONSTANT_EVALUATED) {
+    const std::size_t hash_value = h(vb);
+    assert(h(vb) == hash_value);
+    LIBCPP_ASSERT(hash_value != 0);
   }
 }