libcxx/test/std/utilities/utility/mem.res/mem.res.global/default_resource.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // UNSUPPORTED: c++03, c++11, c++14
  10 // TODO: Change to XFAIL once https://github.com/llvm/llvm-project/issues/40340 is fixed
  11 // UNSUPPORTED: availability-pmr-missing
  12
  13 // test_memory_resource requires RTTI for dynamic_cast
  14 // UNSUPPORTED: no-rtti
  15
  16 // <memory_resource>
  17
  18 //-----------------------------------------------------------------------------
  19 // TESTING memory_resource * get_default_resource() noexcept;
  20 //         memory_resource * set_default_resource(memory_resource*) noexcept;
  21 //
  22 // Concerns:
  23 //  A) 'get_default_resource()' returns a non-null memory_resource pointer.
  24 //  B) 'get_default_resource()' returns the value set by the last call to
  25 //     'set_default_resource(...)' and 'new_delete_resource()' if no call
  26 //     to 'set_default_resource(...)' has occurred.
  27 //  C) 'set_default_resource(...)' returns the previous value of the default
  28 //     resource.
  29 //  D) 'set_default_resource(T* p)' for a non-null 'p' sets the default resource
  30 //     to be 'p'.
  31 //  E) 'set_default_resource(null)' sets the default resource to
  32 //     'new_delete_resource()'.
  33 //  F) 'get_default_resource' and 'set_default_resource' are noexcept.
  34
  35 #include <memory_resource>
  36 #include <cassert>
  37
  38 #include "test_std_memory_resource.h"
  39
  40 using namespace std::pmr;
  41
  42 int main(int, char**) {
  43   TestResource R;
  44   { // Test (A) and (B)
  45     memory_resource* p = get_default_resource();
  46     assert(p != nullptr);
  47     assert(p == new_delete_resource());
  48     assert(p == get_default_resource());
  49   }
  50   { // Test (C) and (D)
  51     memory_resource* expect = &R;
  52     memory_resource* old    = set_default_resource(expect);
  53     assert(old != nullptr);
  54     assert(old == new_delete_resource());
  55
  56     memory_resource* p = get_default_resource();
  57     assert(p != nullptr);
  58     assert(p == expect);
  59     assert(p == get_default_resource());
  60   }
  61   { // Test (E)
  62     memory_resource* old = set_default_resource(nullptr);
  63     assert(old == &R);
  64     memory_resource* p = get_default_resource();
  65     assert(p != nullptr);
  66     assert(p == new_delete_resource());
  67     assert(p == get_default_resource());
  68   }
  69   { // Test (F)
  70     static_assert(noexcept(get_default_resource()), "get_default_resource() must be noexcept");
  71
  72     static_assert(noexcept(set_default_resource(nullptr)), "set_default_resource() must be noexcept");
  73   }
  74
  75   return 0;
  76 }