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stdarray.pass.cpp (3615B)


      1 // -*- C++ -*-
      2 //===------------------------------ span ---------------------------------===//
      3 //
      4 //                     The LLVM Compiler Infrastructure
      5 //
      6 // This file is dual licensed under the MIT and the University of Illinois Open
      7 // Source Licenses. See LICENSE.TXT for details.
      8 //
      9 //===---------------------------------------------------------------------===//
     10 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
     11 
     12 // <span>
     13 
     14 // template<size_t N>
     15 //     constexpr span(array<value_type, N>& arr) noexcept;
     16 // template<size_t N>
     17 //     constexpr span(const array<value_type, N>& arr) noexcept;
     18 //
     19 // Remarks: These constructors shall not participate in overload resolution unless:
     20 //   — extent == dynamic_extent || N == extent is true, and
     21 //   — remove_pointer_t<decltype(data(arr))>(*)[] is convertible to ElementType(*)[].
     22 //
     23 
     24 
     25 #include <span>
     26 #include <cassert>
     27 #include <string>
     28 
     29 #include "test_macros.h"
     30 // std::array is explicitly allowed to be initialized with A a = { init-list };.
     31 // Disable the missing braces warning for this reason.
     32 #include "disable_missing_braces_warning.h"
     33 
     34 
     35 void checkCV()
     36 {
     37     std::array<int, 3> arr  = {1,2,3};
     38 //  STL says these are not cromulent
     39 //  std::array<const int,3> carr = {4,5,6};
     40 //  std::array<volatile int, 3> varr = {7,8,9};
     41 //  std::array<const volatile int, 3> cvarr = {1,3,5};
     42 
     43 //  Types the same (dynamic sized)
     44     {
     45     std::span<               int> s1{  arr};    // a span<               int> pointing at int.
     46     }
     47 
     48 //  Types the same (static sized)
     49     {
     50     std::span<               int,3> s1{  arr};  // a span<               int> pointing at int.
     51     }
     52 
     53 
     54 //  types different (dynamic sized)
     55     {
     56     std::span<const          int> s1{ arr};     // a span<const          int> pointing at int.
     57     std::span<      volatile int> s2{ arr};     // a span<      volatile int> pointing at int.
     58     std::span<      volatile int> s3{ arr};     // a span<      volatile int> pointing at const int.
     59     std::span<const volatile int> s4{ arr};     // a span<const volatile int> pointing at int.
     60     }
     61 
     62 //  types different (static sized)
     63     {
     64     std::span<const          int,3> s1{ arr};   // a span<const          int> pointing at int.
     65     std::span<      volatile int,3> s2{ arr};   // a span<      volatile int> pointing at int.
     66     std::span<      volatile int,3> s3{ arr};   // a span<      volatile int> pointing at const int.
     67     std::span<const volatile int,3> s4{ arr};   // a span<const volatile int> pointing at int.
     68     }
     69 }
     70 
     71 
     72 template <typename T>
     73 constexpr bool testConstexprSpan()
     74 {
     75     constexpr std::array<T,2> val = { T(), T() };
     76     ASSERT_NOEXCEPT(std::span<const T>   {val});
     77     ASSERT_NOEXCEPT(std::span<const T, 2>{val});
     78     std::span<const T>    s1{val};
     79     std::span<const T, 2> s2{val};
     80     return
     81         s1.data() == &val[0] && s1.size() == 2
     82     &&  s2.data() == &val[0] && s2.size() == 2;
     83 }
     84 
     85 
     86 template <typename T>
     87 void testRuntimeSpan()
     88 {
     89     std::array<T,2> val;
     90     ASSERT_NOEXCEPT(std::span<T>   {val});
     91     ASSERT_NOEXCEPT(std::span<T, 2>{val});
     92     std::span<T>    s1{val};
     93     std::span<T, 2> s2{val};
     94     assert(s1.data() == &val[0] && s1.size() == 2);
     95     assert(s2.data() == &val[0] && s2.size() == 2);
     96 }
     97 
     98 struct A{};
     99 
    100 int main ()
    101 {
    102     static_assert(testConstexprSpan<int>(),    "");
    103     static_assert(testConstexprSpan<long>(),   "");
    104     static_assert(testConstexprSpan<double>(), "");
    105     static_assert(testConstexprSpan<A>(),      "");
    106 
    107     testRuntimeSpan<int>();
    108     testRuntimeSpan<long>();
    109     testRuntimeSpan<double>();
    110     testRuntimeSpan<std::string>();
    111     testRuntimeSpan<A>();
    112 
    113     checkCV();
    114 }