libcxx/test/std/strings/basic.string/string.starts_with/starts_with.string_view.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 // UNSUPPORTED: c++03, c++11, c++14, c++17
   9
  10 // <string>
  11
  12 // constexpr bool starts_with(string_view x) const noexcept;
  13
  14 #include <string>
  15 #include <cassert>
  16
  17 #include "test_macros.h"
  18
  19 template <class CharT, template <class> class Alloc>
  20 constexpr void test_string() {
  21   using S       = std::basic_string<CharT, std::char_traits<CharT>, Alloc<CharT> >;
  22   using SV      = std::basic_string_view<CharT, std::char_traits<CharT> >;
  23   const char* s = "abcde";
  24
  25   S s0;
  26   S s1{s, 1};
  27   S s2{s, 2};
  28   //  S   s3  { s, 3 };
  29   //  S   s4  { s, 4 };
  30   //  S   s5  { s, 5 };
  31   S sNot{"def", 3};
  32
  33   SV sv0;
  34   SV sv1{s, 1};
  35   SV sv2{s, 2};
  36   SV sv3{s, 3};
  37   SV sv4{s, 4};
  38   SV sv5{s, 5};
  39   SV svNot{"def", 3};
  40
  41   ASSERT_NOEXCEPT(s0.starts_with(sv0));
  42
  43   assert(s0.starts_with(sv0));
  44   assert(!s0.starts_with(sv1));
  45
  46   assert(s1.starts_with(sv0));
  47   assert(s1.starts_with(sv1));
  48   assert(!s1.starts_with(sv2));
  49   assert(!s1.starts_with(sv3));
  50   assert(!s1.starts_with(sv4));
  51   assert(!s1.starts_with(sv5));
  52   assert(!s1.starts_with(svNot));
  53
  54   assert(s2.starts_with(sv0));
  55   assert(s2.starts_with(sv1));
  56   assert(s2.starts_with(sv2));
  57   assert(!s2.starts_with(sv3));
  58   assert(!s2.starts_with(sv4));
  59   assert(!s2.starts_with(sv5));
  60   assert(!s2.starts_with(svNot));
  61
  62   assert(sNot.starts_with(sv0));
  63   assert(!sNot.starts_with(sv1));
  64   assert(!sNot.starts_with(sv2));
  65   assert(!sNot.starts_with(sv3));
  66   assert(!sNot.starts_with(sv4));
  67   assert(!sNot.starts_with(sv5));
  68   assert(sNot.starts_with(svNot));
  69 }
  70
  71 constexpr bool test() {
  72   test_string<char, std::allocator>();
  73
  74   return true;
  75 }
  76
  77 int main(int, char**) {
  78   test();
  79   static_assert(test());
  80
  81   return 0;
  82 }