libcxx/test/std/input.output/iostream.format/quoted.manip/quoted_traits.compile.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 // UNSUPPORTED: c++03, c++11
  10
  11 // <iomanip>
  12
  13 // std::quoted
  14 //   Verify that the result type of std::quoted can be streamed to
  15 //   (and from) ostreams with the correct CharTraits, and not those
  16 //   with the wrong CharTraits. To avoid our having to create working
  17 //   ostreams with weird CharTraits, this is a compile-only test.
  18
  19 #include <iomanip>
  20 #include <istream>
  21 #include <ostream>
  22 #include <string>
  23 #include <string_view>
  24 #include <type_traits>
  25
  26 #include "test_allocator.h"
  27 #include "test_macros.h"
  28
  29 template<class IS, class Q>
  30 decltype(std::declval<IS>() >> std::declval<Q>(), std::true_type())
  31 has_rightshift_impl(int) { return std::true_type(); }
  32
  33 template<class IS, class Q>
  34 std::false_type
  35 has_rightshift_impl(long) { return std::false_type(); }
  36
  37 template<class IS, class Q>
  38 struct HasRightShift : decltype(has_rightshift_impl<IS, Q>(0)) {};
  39
  40 template<class OS, class Q>
  41 decltype(std::declval<OS>() << std::declval<Q>(), std::true_type())
  42 has_leftshift_impl(int) { return std::true_type(); }
  43
  44 template<class OS, class Q>
  45 std::false_type
  46 has_leftshift_impl(long) { return std::false_type(); }
  47
  48 template<class OS, class Q>
  49 struct HasLeftShift : decltype(has_leftshift_impl<OS, Q>(0)) {};
  50
  51 template<class CharT>
  52 struct FakeCharTraits : std::char_traits<CharT> {};
  53
  54 void test_string_literal()
  55 {
  56   using Q = decltype(std::quoted("hello"));
  57   static_assert( HasLeftShift<std::ostream&, Q>::value, "");
  58   static_assert(!HasRightShift<std::istream&, Q>::value, "");
  59   static_assert( HasLeftShift<std::basic_ostream<char, FakeCharTraits<char>>&, Q>::value, "");
  60   static_assert(!HasRightShift<std::basic_istream<char, FakeCharTraits<char>>&, Q>::value, "");
  61
  62 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  63   using WQ = decltype(std::quoted(L"hello"));
  64   static_assert( HasLeftShift<std::wostream&, WQ>::value, "");
  65   static_assert(!HasRightShift<std::wistream&, WQ>::value, "");
  66   static_assert( HasLeftShift<std::basic_ostream<wchar_t, FakeCharTraits<wchar_t>>&, WQ>::value, "");
  67   static_assert(!HasRightShift<std::basic_istream<wchar_t, FakeCharTraits<wchar_t>>&, WQ>::value, "");
  68
  69   static_assert(!HasLeftShift<std::ostream&, WQ>::value, "");
  70   static_assert(!HasLeftShift<std::wostream&, Q>::value, "");
  71 #endif // TEST_HAS_NO_WIDE_CHARACTERS
  72 }
  73
  74 void test_std_string()
  75 {
  76   std::string s = "hello";
  77   const auto& cs = s;
  78   using Q = decltype(std::quoted(s));
  79   using CQ = decltype(std::quoted(cs));
  80   static_assert( HasLeftShift<std::ostream&, Q>::value, "");
  81   static_assert( HasRightShift<std::istream&, Q>::value, "");
  82   static_assert( HasLeftShift<std::ostream&, CQ>::value, "");
  83   static_assert(!HasRightShift<std::istream&, CQ>::value, "");
  84   static_assert(!HasLeftShift<std::basic_ostream<char, FakeCharTraits<char>>&, Q>::value, "");
  85   static_assert(!HasRightShift<std::basic_istream<char, FakeCharTraits<char>>&, Q>::value, "");
  86   static_assert(!HasLeftShift<std::basic_ostream<char, FakeCharTraits<char>>&, CQ>::value, "");
  87   static_assert(!HasRightShift<std::basic_istream<char, FakeCharTraits<char>>&, CQ>::value, "");
  88
  89   std::basic_string<char, FakeCharTraits<char>, test_allocator<char>> st = "hello";
  90   const auto& cst = st;
  91   using QT = decltype(std::quoted(st));
  92   using CQT = decltype(std::quoted(cst));
  93   static_assert(!HasLeftShift<std::ostream&, QT>::value, "");
  94   static_assert(!HasRightShift<std::istream&, QT>::value, "");
  95   static_assert(!HasLeftShift<std::ostream&, CQT>::value, "");
  96   static_assert(!HasRightShift<std::istream&, CQT>::value, "");
  97   static_assert( HasLeftShift<std::basic_ostream<char, FakeCharTraits<char>>&, QT>::value, "");
  98   static_assert( HasRightShift<std::basic_istream<char, FakeCharTraits<char>>&, QT>::value, "");
  99   static_assert( HasLeftShift<std::basic_ostream<char, FakeCharTraits<char>>&, CQT>::value, "");
 100   static_assert(!HasRightShift<std::basic_istream<char, FakeCharTraits<char>>&, CQT>::value, "");
 101
 102 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
 103   std::wstring ws = L"hello";
 104   const auto& cws = ws;
 105   using WQ = decltype(std::quoted(ws));
 106   using CWQ = decltype(std::quoted(cws));
 107   static_assert( HasLeftShift<std::wostream&, WQ>::value, "");
 108   static_assert( HasRightShift<std::wistream&, WQ>::value, "");
 109   static_assert( HasLeftShift<std::wostream&, CWQ>::value, "");
 110   static_assert(!HasRightShift<std::wistream&, CWQ>::value, "");
 111   static_assert(!HasLeftShift<std::basic_ostream<wchar_t, FakeCharTraits<wchar_t>>&, WQ>::value, "");
 112   static_assert(!HasRightShift<std::basic_istream<wchar_t, FakeCharTraits<wchar_t>>&, WQ>::value, "");
 113   static_assert(!HasLeftShift<std::basic_ostream<wchar_t, FakeCharTraits<wchar_t>>&, CWQ>::value, "");
 114   static_assert(!HasRightShift<std::basic_istream<wchar_t, FakeCharTraits<wchar_t>>&, CWQ>::value, "");
 115
 116   static_assert(!HasLeftShift<std::ostream&, WQ>::value, "");
 117   static_assert(!HasLeftShift<std::wostream&, Q>::value, "");
 118 #endif // TEST_HAS_NO_WIDE_CHARACTERS
 119 }
 120
 121 void test_std_string_view()
 122 {
 123   std::string_view s = "hello";
 124   const auto& cs = s;
 125   using Q = decltype(std::quoted(s));
 126   using CQ = decltype(std::quoted(cs));
 127   static_assert( HasLeftShift<std::ostream&, Q>::value, "");
 128   static_assert(!HasRightShift<std::istream&, Q>::value, "");
 129   static_assert( HasLeftShift<std::ostream&, CQ>::value, "");
 130   static_assert(!HasRightShift<std::istream&, CQ>::value, "");
 131   static_assert(!HasLeftShift<std::basic_ostream<char, FakeCharTraits<char>>&, Q>::value, "");
 132   static_assert(!HasRightShift<std::basic_istream<char, FakeCharTraits<char>>&, Q>::value, "");
 133   static_assert(!HasLeftShift<std::basic_ostream<char, FakeCharTraits<char>>&, CQ>::value, "");
 134   static_assert(!HasRightShift<std::basic_istream<char, FakeCharTraits<char>>&, CQ>::value, "");
 135
 136   std::basic_string_view<char, FakeCharTraits<char>> st = "hello";
 137   const auto& cst = st;
 138   using QT = decltype(std::quoted(st));
 139   using CQT = decltype(std::quoted(cst));
 140   static_assert(!HasLeftShift<std::ostream&, QT>::value, "");
 141   static_assert(!HasRightShift<std::istream&, QT>::value, "");
 142   static_assert(!HasLeftShift<std::ostream&, CQT>::value, "");
 143   static_assert(!HasRightShift<std::istream&, CQT>::value, "");
 144   static_assert( HasLeftShift<std::basic_ostream<char, FakeCharTraits<char>>&, QT>::value, "");
 145   static_assert(!HasRightShift<std::basic_istream<char, FakeCharTraits<char>>&, QT>::value, "");
 146   static_assert( HasLeftShift<std::basic_ostream<char, FakeCharTraits<char>>&, CQT>::value, "");
 147   static_assert(!HasRightShift<std::basic_istream<char, FakeCharTraits<char>>&, CQT>::value, "");
 148
 149 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
 150   std::wstring_view ws = L"hello";
 151   const auto& cws = ws;
 152   using WQ = decltype(std::quoted(ws));
 153   using CWQ = decltype(std::quoted(cws));
 154   static_assert( HasLeftShift<std::wostream&, WQ>::value, "");
 155   static_assert(!HasRightShift<std::wistream&, WQ>::value, "");
 156   static_assert( HasLeftShift<std::wostream&, CWQ>::value, "");
 157   static_assert(!HasRightShift<std::wistream&, CWQ>::value, "");
 158   static_assert(!HasLeftShift<std::basic_ostream<wchar_t, FakeCharTraits<wchar_t>>&, WQ>::value, "");
 159   static_assert(!HasRightShift<std::basic_istream<wchar_t, FakeCharTraits<wchar_t>>&, WQ>::value, "");
 160   static_assert(!HasLeftShift<std::basic_ostream<wchar_t, FakeCharTraits<wchar_t>>&, CWQ>::value, "");
 161   static_assert(!HasRightShift<std::basic_istream<wchar_t, FakeCharTraits<wchar_t>>&, CWQ>::value, "");
 162
 163   static_assert(!HasLeftShift<std::ostream&, WQ>::value, "");
 164   static_assert(!HasLeftShift<std::wostream&, Q>::value, "");
 165 #endif // TEST_HAS_NO_WIDE_CHARACTERS
 166 }