libcxx/test/std/strings/basic.string/string.ops/string.accessors/data.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 // <string>
  10
  11 // const charT* data() const; // constexpr since C++20
  12 //       charT* data();   // C++17, constexpr since C++20
  13
  14 #include <string>
  15 #include <cassert>
  16
  17 #include "test_macros.h"
  18 #include "min_allocator.h"
  19
  20 template <class S>
  21 TEST_CONSTEXPR_CXX20 void test_const(const S& s) {
  22   typedef typename S::traits_type T;
  23   const typename S::value_type* str = s.data();
  24   if (s.size() > 0) {
  25     assert(T::compare(str, &s[0], s.size()) == 0);
  26     assert(T::eq(str[s.size()], typename S::value_type()));
  27   } else
  28     assert(T::eq(str[0], typename S::value_type()));
  29 }
  30
  31 template <class S>
  32 TEST_CONSTEXPR_CXX20 void test_nonconst(S& s) {
  33   typedef typename S::traits_type T;
  34   typename S::value_type* str = s.data();
  35   if (s.size() > 0) {
  36     assert(T::compare(str, &s[0], s.size()) == 0);
  37     assert(T::eq(str[s.size()], typename S::value_type()));
  38   } else
  39     assert(T::eq(str[0], typename S::value_type()));
  40 }
  41
  42 template <class S>
  43 TEST_CONSTEXPR_CXX20 void test_string() {
  44   test_const(S(""));
  45   test_const(S("abcde"));
  46   test_const(S("abcdefghij"));
  47   test_const(S("abcdefghijklmnopqrst"));
  48 #if TEST_STD_VER > 14
  49   {
  50     S s1("");
  51     test_nonconst(s1);
  52     S s2("abcde");
  53     test_nonconst(s2);
  54     S s3("abcdefghij");
  55     test_nonconst(s3);
  56     S s4("abcdefghijklmnopqrst");
  57     test_nonconst(s4);
  58   }
  59 #endif
  60 }
  61
  62 TEST_CONSTEXPR_CXX20 bool test() {
  63   test_string<std::string>();
  64 #if TEST_STD_VER >= 11
  65   test_string<std::basic_string<char, std::char_traits<char>, min_allocator<char> > >();
  66 #endif
  67
  68   return true;
  69 }
  70
  71 int main(int, char**) {
  72   test();
  73 #if TEST_STD_VER > 17
  74   static_assert(test());
  75 #endif
  76
  77   return 0;
  78 }