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      1 //===----------------------------------------------------------------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is dual licensed under the MIT and the University of Illinois Open
      6 // Source Licenses. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 
     10 // REQUIRES: c++experimental
     11 // UNSUPPORTED: c++98, c++03
     12 
     13 // <experimental/memory_resource>
     14 
     15 // template <class T> class polymorphic_allocator
     16 
     17 // T* polymorphic_allocator<T>::allocate(size_t n)
     18 
     19 #include <experimental/memory_resource>
     20 #include <limits>
     21 #include <memory>
     22 #include <exception>
     23 #include <type_traits>
     24 #include <cassert>
     25 
     26 #include "test_macros.h"
     27 #include "test_memory_resource.hpp"
     28 
     29 namespace ex = std::experimental::pmr;
     30 
     31 template <size_t S, size_t Align>
     32 void testForSizeAndAlign() {
     33     using T = typename std::aligned_storage<S, Align>::type;
     34     TestResource R;
     35     ex::polymorphic_allocator<T> a(&R);
     36 
     37     for (int N = 1; N <= 5; ++N) {
     38         auto ret = a.allocate(N);
     39         assert(R.checkAlloc(ret, N * sizeof(T), alignof(T)));
     40 
     41         a.deallocate(ret, N);
     42         R.reset();
     43     }
     44 }
     45 
     46 #ifndef TEST_HAS_NO_EXCEPTIONS
     47 template <size_t S>
     48 void testAllocForSizeThrows() {
     49     using T = typename std::aligned_storage<S>::type;
     50     using Alloc = ex::polymorphic_allocator<T>;
     51     using Traits = std::allocator_traits<Alloc>;
     52     NullResource R;
     53     Alloc a(&R);
     54 
     55     // Test that allocating exactly the max size does not throw.
     56     size_t maxSize = Traits::max_size(a);
     57     try {
     58         a.allocate(maxSize);
     59     } catch (...) {
     60         assert(false);
     61     }
     62 
     63     size_t sizeTypeMax = std::numeric_limits<std::size_t>::max();
     64     if (maxSize != sizeTypeMax)
     65     {
     66         // Test that allocating size_t(~0) throws bad alloc.
     67         try {
     68             a.allocate(sizeTypeMax);
     69             assert(false);
     70         } catch (std::exception const&) {
     71         }
     72 
     73         // Test that allocating even one more than the max size does throw.
     74         size_t overSize = maxSize + 1;
     75         try {
     76             a.allocate(overSize);
     77             assert(false);
     78         } catch (std::exception const&) {
     79         }
     80     }
     81 }
     82 #endif // TEST_HAS_NO_EXCEPTIONS
     83 
     84 int main()
     85 {
     86     {
     87         ex::polymorphic_allocator<int> a;
     88         static_assert(std::is_same<decltype(a.allocate(0)), int*>::value, "");
     89         static_assert(!noexcept(a.allocate(0)), "");
     90     }
     91     {
     92         constexpr std::size_t MA = alignof(std::max_align_t);
     93         testForSizeAndAlign<1, 1>();
     94         testForSizeAndAlign<1, 2>();
     95         testForSizeAndAlign<1, MA>();
     96         testForSizeAndAlign<2, 2>();
     97         testForSizeAndAlign<73, alignof(void*)>();
     98         testForSizeAndAlign<73, MA>();
     99         testForSizeAndAlign<13, MA>();
    100     }
    101 #ifndef TEST_HAS_NO_EXCEPTIONS
    102     {
    103         testAllocForSizeThrows<1>();
    104         testAllocForSizeThrows<2>();
    105         testAllocForSizeThrows<4>();
    106         testAllocForSizeThrows<8>();
    107         testAllocForSizeThrows<16>();
    108         testAllocForSizeThrows<73>();
    109         testAllocForSizeThrows<13>();
    110     }
    111 #endif
    112 }
    113