libcxx/test/std/containers/views/span.elem/op_idx.pass.cpp

   1 // -*- C++ -*-
   2 //===------------------------------ span ---------------------------------===//
   3 //
   4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   5 // See https://llvm.org/LICENSE.txt for license information.
   6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   7 //
   8 //===---------------------------------------------------------------------===//
   9 // UNSUPPORTED: c++03, c++11, c++14, c++17
  10
  11 // <span>
  12
  13 // constexpr reference operator[](size_type idx) const;
  14 // constexpr reference operator()(size_type idx) const;
  15 //
  16
  17
  18 #include <span>
  19 #include <cassert>
  20 #include <string>
  21
  22 #include "test_macros.h"
  23
  24
  25 template <typename Span>
  26 constexpr bool testConstexprSpan(Span sp, size_t idx)
  27 {
  28     LIBCPP_ASSERT(noexcept(sp[idx]));
  29
  30     typename Span::reference r1 = sp[idx];
  31     typename Span::reference r2 = *(sp.data() + idx);
  32     return r1 == r2;
  33 }
  34
  35
  36 template <typename Span>
  37 void testRuntimeSpan(Span sp, size_t idx)
  38 {
  39     LIBCPP_ASSERT(noexcept(sp[idx]));
  40
  41     typename Span::reference r1 = sp[idx];
  42     typename Span::reference r2 = *(sp.data() + idx);
  43     assert(r1 == r2);
  44 }
  45
  46 struct A{};
  47 constexpr int iArr1[] = { 0,  1,  2,  3,  4,  5,  6,  7,  8,  9};
  48           int iArr2[] = {10, 11, 12, 13, 14, 15, 16, 17, 18, 19};
  49
  50 int main(int, char**)
  51 {
  52     static_assert(testConstexprSpan(std::span<const int>(iArr1, 1), 0), "");
  53
  54     static_assert(testConstexprSpan(std::span<const int>(iArr1, 2), 0), "");
  55     static_assert(testConstexprSpan(std::span<const int>(iArr1, 2), 1), "");
  56
  57     static_assert(testConstexprSpan(std::span<const int>(iArr1, 3), 0), "");
  58     static_assert(testConstexprSpan(std::span<const int>(iArr1, 3), 1), "");
  59     static_assert(testConstexprSpan(std::span<const int>(iArr1, 3), 2), "");
  60
  61     static_assert(testConstexprSpan(std::span<const int>(iArr1, 4), 0), "");
  62     static_assert(testConstexprSpan(std::span<const int>(iArr1, 4), 1), "");
  63     static_assert(testConstexprSpan(std::span<const int>(iArr1, 4), 2), "");
  64     static_assert(testConstexprSpan(std::span<const int>(iArr1, 4), 3), "");
  65
  66
  67     static_assert(testConstexprSpan(std::span<const int, 1>(iArr1, 1), 0), "");
  68
  69     static_assert(testConstexprSpan(std::span<const int, 2>(iArr1, 2), 0), "");
  70     static_assert(testConstexprSpan(std::span<const int, 2>(iArr1, 2), 1), "");
  71
  72     static_assert(testConstexprSpan(std::span<const int, 3>(iArr1, 3), 0), "");
  73     static_assert(testConstexprSpan(std::span<const int, 3>(iArr1, 3), 1), "");
  74     static_assert(testConstexprSpan(std::span<const int, 3>(iArr1, 3), 2), "");
  75
  76     static_assert(testConstexprSpan(std::span<const int, 4>(iArr1, 4), 0), "");
  77     static_assert(testConstexprSpan(std::span<const int, 4>(iArr1, 4), 1), "");
  78     static_assert(testConstexprSpan(std::span<const int, 4>(iArr1, 4), 2), "");
  79     static_assert(testConstexprSpan(std::span<const int, 4>(iArr1, 4), 3), "");
  80
  81
  82     testRuntimeSpan(std::span<int>(iArr2, 1), 0);
  83
  84     testRuntimeSpan(std::span<int>(iArr2, 2), 0);
  85     testRuntimeSpan(std::span<int>(iArr2, 2), 1);
  86
  87     testRuntimeSpan(std::span<int>(iArr2, 3), 0);
  88     testRuntimeSpan(std::span<int>(iArr2, 3), 1);
  89     testRuntimeSpan(std::span<int>(iArr2, 3), 2);
  90
  91     testRuntimeSpan(std::span<int>(iArr2, 4), 0);
  92     testRuntimeSpan(std::span<int>(iArr2, 4), 1);
  93     testRuntimeSpan(std::span<int>(iArr2, 4), 2);
  94     testRuntimeSpan(std::span<int>(iArr2, 4), 3);
  95
  96
  97     testRuntimeSpan(std::span<int, 1>(iArr2, 1), 0);
  98
  99     testRuntimeSpan(std::span<int, 2>(iArr2, 2), 0);
 100     testRuntimeSpan(std::span<int, 2>(iArr2, 2), 1);
 101
 102     testRuntimeSpan(std::span<int, 3>(iArr2, 3), 0);
 103     testRuntimeSpan(std::span<int, 3>(iArr2, 3), 1);
 104     testRuntimeSpan(std::span<int, 3>(iArr2, 3), 2);
 105
 106     testRuntimeSpan(std::span<int, 4>(iArr2, 4), 0);
 107     testRuntimeSpan(std::span<int, 4>(iArr2, 4), 1);
 108     testRuntimeSpan(std::span<int, 4>(iArr2, 4), 2);
 109     testRuntimeSpan(std::span<int, 4>(iArr2, 4), 3);
 110
 111     std::string s;
 112     testRuntimeSpan(std::span<std::string>   (&s, 1), 0);
 113     testRuntimeSpan(std::span<std::string, 1>(&s, 1), 0);
 114
 115   return 0;
 116 }