Implement LWG 2946, 3075 and 3076. Reviewed as https://reviews.llvm.org/D48616

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@336132 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/strings/basic.string/string.cons/copy_assignment.pass.cpp

@@ -68,4 +68,13 @@ int main()
          S("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"));
     }
 #endif
+
+#if TEST_STD_VER > 3
+    {   // LWG 2946
+    std::string s;
+    s = {"abc", 1};
+    assert(s.size() == 1);
+    assert(s == "a");
+    }
+#endif
 }

test/std/strings/basic.string/string.cons/default_noexcept.pass.cpp

@@ -22,13 +22,6 @@
 #include "test_macros.h"
 #include "test_allocator.h"
 
-template <class T>
-struct some_alloc
-{
-    typedef T value_type;
-    some_alloc(const some_alloc&);
-};
-
 int main()
 {
     {
@@ -40,7 +33,7 @@ int main()
         static_assert(std::is_nothrow_default_constructible<C>::value, "");
     }
     {
-        typedef std::basic_string<char, std::char_traits<char>, some_alloc<char>> C;
+        typedef std::basic_string<char, std::char_traits<char>, limited_allocator<char, 10>> C;
         static_assert(!std::is_nothrow_default_constructible<C>::value, "");
     }
 }

test/std/strings/basic.string/string.cons/dtor_noexcept.pass.cpp

@@ -20,11 +20,12 @@
 #include "test_allocator.h"
 
 template <class T>
-struct some_alloc
+struct throwing_alloc
 {
     typedef T value_type;
-    some_alloc(const some_alloc&);
-    ~some_alloc() noexcept(false);
+    throwing_alloc(const throwing_alloc&);
+    T *allocate(size_t);
+    ~throwing_alloc() noexcept(false);
 };
 
 // Test that it's possible to take the address of basic_string's destructors
@@ -44,7 +45,7 @@ int main()
     }
 #if defined(_LIBCPP_VERSION)
     {
-        typedef std::basic_string<char, std::char_traits<char>, some_alloc<char>> C;
+        typedef std::basic_string<char, std::char_traits<char>, throwing_alloc<char>> C;
         static_assert(!std::is_nothrow_destructible<C>::value, "");
     }
 #endif // _LIBCPP_VERSION

test/std/strings/basic.string/string.cons/implicit_deduction_guides.pass.cpp

@@ -36,7 +36,7 @@ using BStr = std::basic_string<T, std::char_traits<T>, Alloc>;
 // (2)  basic_string(A const&) - BROKEN
 // (3)  basic_string(size_type, CharT, const A& = A())
 // (4)  basic_string(BS const&, size_type, A const& = A())
-// (5)  basic_string(BS const&, size_type, size_type, A const& = A()) - PARTIALLY BROKEN
+// (5)  basic_string(BS const&, size_type, size_type, A const& = A())
 // (6)  basic_string(const CharT*, size_type, A const& = A())
 // (7)  basic_string(const CharT*, A const& = A())
 // (8)  basic_string(InputIt, InputIt, A const& = A()) - BROKEN
@@ -46,7 +46,7 @@ using BStr = std::basic_string<T, std::char_traits<T>, Alloc>;
 // (12) basic_string(BS&&, A const&)
 // (13) basic_string(initializer_list<CharT>, A const& = A())
 // (14) basic_string(BSV, A const& = A())
-// (15) basic_string(const T&, size_type, size_type, A const& = A()) - BROKEN
+// (15) basic_string(const T&, size_type, size_type, A const& = A())
 int main()
 {
   using TestSizeT = test_allocator<char>::size_type;
@@ -106,7 +106,6 @@ int main()
     assert(w == L"def");
   }
   { // Testing (5) w/o allocator
-#if 0 // FIXME: This doesn't work
     const std::string sin("abc");
     std::basic_string s(sin, (size_t)1, (size_t)3);
     ASSERT_SAME_TYPE(decltype(s), std::string);
@@ -119,7 +118,6 @@ int main()
     std::basic_string w(win, (TestSizeT)2, (TestSizeT)3);
     ASSERT_SAME_TYPE(decltype(w), WStr);
     assert(w == L"cde");
-#endif
   }
   { // Testing (5) w/ allocator
     const std::string sin("abc");
@@ -178,20 +176,19 @@ int main()
     assert(w == L"abcdef");
   }
   { // (8) w/o allocator
-    // This overload isn't compatible with implicit deduction guides as
-    // specified in the standard.
-    // FIXME: Propose adding an explicit guide to the standard?
-  }
-  { // (8) w/ allocator
-    // This overload isn't compatible with implicit deduction guides as
-    // specified in the standard.
-    // FIXME: Propose adding an explicit guide to the standard?
-#if 0
     using It = input_iterator<const char*>;
     const char* input = "abcdef";
     std::basic_string s(It(input), It(input + 3), std::allocator<char>{});
     ASSERT_SAME_TYPE(decltype(s), std::string);
-#endif
+    assert(s == "abc");
+  }
+  { // (8) w/ allocator
+    using ExpectW = std::basic_string<wchar_t, std::char_traits<wchar_t>, test_allocator<wchar_t>>;
+    using It = input_iterator<const wchar_t*>;
+    const wchar_t* input = L"abcdef";
+    std::basic_string s(It(input), It(input + 3), test_allocator<wchar_t>{});
+    ASSERT_SAME_TYPE(decltype(s), ExpectW);
+    assert(s == L"abc");
   }
   { // Testing (9)
     const std::string sin("abc");
@@ -293,8 +290,28 @@ int main()
     ASSERT_SAME_TYPE(decltype(w), ExpectW);
     assert(w == L"abcdef");
   }
-  { // Testing (15)
-    // This overload isn't compatible with implicit deduction guides as
-    // specified in the standard.
+  { // Testing (15) w/o allocator
+    std::string s0("abc");
+    std::basic_string s(s0, 1, 1);
+    ASSERT_SAME_TYPE(decltype(s), std::string);
+    assert(s == "b");
+
+    std::wstring w0(L"abcdef");
+    std::basic_string w(w0, 2, 2);
+    ASSERT_SAME_TYPE(decltype(w), std::wstring);
+    assert(w == L"cd");
+  }
+  { // Testing (15) w/ allocator
+    using ExpectS = std::basic_string<char, std::char_traits<char>, test_allocator<char>>;
+    ExpectS s0("abc");
+    std::basic_string s(s0, 1, 1, test_allocator<char>{4});
+    ASSERT_SAME_TYPE(decltype(s), ExpectS);
+    assert(s == "b");
+
+    using ExpectW = std::basic_string<wchar_t, std::char_traits<wchar_t>, test_allocator<wchar_t>>;
+    ExpectW w0(L"abcdef");
+    std::basic_string w(w0, 2, 2, test_allocator<wchar_t>{6});
+    ASSERT_SAME_TYPE(decltype(w), ExpectW);
+    assert(w == L"cd");
   }
 }

test/std/strings/basic.string/string.cons/move_assign_noexcept.pass.cpp

@@ -32,6 +32,7 @@ struct some_alloc
 {
     typedef T value_type;
     some_alloc(const some_alloc&);
+    T *allocate(size_t);
 };
 
 template <class T>
@@ -41,6 +42,7 @@ struct some_alloc2
 
     some_alloc2() {}
     some_alloc2(const some_alloc2&);
+    T *allocate(size_t);
     void deallocate(void*, unsigned) {}
 
     typedef std::false_type propagate_on_container_move_assignment;
@@ -54,6 +56,7 @@ struct some_alloc3
 
     some_alloc3() {}
     some_alloc3(const some_alloc3&);
+    T *allocate(size_t);
     void deallocate(void*, unsigned) {}
 
     typedef std::false_type propagate_on_container_move_assignment;

test/std/strings/basic.string/string.cons/move_noexcept.pass.cpp

@@ -22,13 +22,6 @@
 #include "test_macros.h"
 #include "test_allocator.h"
 
-template <class T>
-struct some_alloc
-{
-    typedef T value_type;
-    some_alloc(const some_alloc&);
-};
-
 int main()
 {
     {
@@ -40,7 +33,7 @@ int main()
         static_assert(std::is_nothrow_move_constructible<C>::value, "");
     }
     {
-        typedef std::basic_string<char, std::char_traits<char>, some_alloc<char>> C;
+        typedef std::basic_string<char, std::char_traits<char>, limited_allocator<char, 10>> C;
 #if TEST_STD_VER <= 14
         static_assert(!std::is_nothrow_move_constructible<C>::value, "");
 #else

test/std/strings/basic.string/string.cons/pointer_size_alloc.pass.cpp

@@ -83,4 +83,12 @@ int main()
     test("123456798012345679801234567980123456798012345679801234567980", 60, A());
     }
 #endif
+
+#if TEST_STD_VER > 3
+    {   // LWG 2946
+    std::string s({"abc", 1});
+    assert(s.size() == 1);
+    assert(s == "a");
+    }
+#endif
 }

test/std/strings/basic.string/string.cons/string_view_deduction.fail.cpp

@@ -0,0 +1,41 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-deduction-guides
+
+// template<class InputIterator>
+//   basic_string(InputIterator begin, InputIterator end,
+//   const Allocator& a = Allocator());
+
+// template<class charT,
+//          class traits,
+//          class Allocator = allocator<charT>
+//          >
+// basic_string(basic_string_view<charT, traits>, const Allocator& = Allocator())
+//   -> basic_string<charT, traits, Allocator>;
+//
+//  The deduction guide shall not participate in overload resolution if Allocator
+//  is a type that does not qualify as an allocator.
+
+
+#include <string>
+#include <string_view>
+#include <iterator>
+#include <cassert>
+#include <cstddef>
+
+int main()
+{
+    {
+    std::string_view sv = "12345678901234";
+    std::basic_string s1{sv, 23}; // expected-error {{no viable constructor or deduction guide for deduction of template arguments of 'basic_string'}}
+    }
+}

test/std/strings/basic.string/string.cons/string_view_deduction.pass.cpp

@@ -0,0 +1,95 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-deduction-guides
+
+// template<class InputIterator>
+//   basic_string(InputIterator begin, InputIterator end,
+//   const Allocator& a = Allocator());
+
+// template<class charT,
+//          class traits,
+//          class Allocator = allocator<charT>
+//          >
+// basic_string(basic_string_view<charT, traits>, const Allocator& = Allocator())
+//   -> basic_string<charT, traits, Allocator>;
+//
+//  The deduction guide shall not participate in overload resolution if Allocator
+//  is a type that does not qualify as an allocator.
+
+
+#include <string>
+#include <string_view>
+#include <iterator>
+#include <memory>
+#include <type_traits>
+#include <cassert>
+#include <cstddef>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+#include "../input_iterator.h"
+#include "min_allocator.h"
+
+int main()
+{
+    {
+    std::string_view sv = "12345678901234";
+    std::basic_string s1(sv);
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                      char>,  "");
+    static_assert(std::is_same_v<S::traits_type,    std::char_traits<char>>, "");
+    static_assert(std::is_same_v<S::allocator_type,   std::allocator<char>>, "");
+    assert(s1.size() == sv.size());
+    assert(s1.compare(0, s1.size(), sv.data(), s1.size()) == 0);
+    }
+
+    {
+    std::string_view sv = "12345678901234";
+    std::basic_string s1{sv, std::allocator<char>{}};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                      char>,  "");
+    static_assert(std::is_same_v<S::traits_type,    std::char_traits<char>>, "");
+    static_assert(std::is_same_v<S::allocator_type,   std::allocator<char>>, "");
+    assert(s1.size() == sv.size());
+    assert(s1.compare(0, s1.size(), sv.data(), s1.size()) == 0);
+    }
+    {
+    std::wstring_view sv = L"12345678901234";
+    std::basic_string s1{sv, test_allocator<wchar_t>{}};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                      wchar_t>,  "");
+    static_assert(std::is_same_v<S::traits_type,    std::char_traits<wchar_t>>, "");
+    static_assert(std::is_same_v<S::allocator_type,   test_allocator<wchar_t>>, "");
+    assert(s1.size() == sv.size());
+    assert(s1.compare(0, s1.size(), sv.data(), s1.size()) == 0);
+    }
+    {
+    std::u16string_view sv = u"12345678901234";
+    std::basic_string s1{sv, min_allocator<char16_t>{}};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                      char16_t>,  "");
+    static_assert(std::is_same_v<S::traits_type,    std::char_traits<char16_t>>, "");
+    static_assert(std::is_same_v<S::allocator_type,    min_allocator<char16_t>>, "");
+    assert(s1.size() == sv.size());
+    assert(s1.compare(0, s1.size(), sv.data(), s1.size()) == 0);
+    }
+    {
+    std::u32string_view sv = U"12345678901234";
+    std::basic_string s1{sv, explicit_allocator<char32_t>{}};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                        char32_t>,  "");
+    static_assert(std::is_same_v<S::traits_type,      std::char_traits<char32_t>>, "");
+    static_assert(std::is_same_v<S::allocator_type, explicit_allocator<char32_t>>, "");
+    assert(s1.size() == sv.size());
+    assert(s1.compare(0, s1.size(), sv.data(), s1.size()) == 0);
+    }
+}

test/std/strings/basic.string/string.cons/string_view_size_size_deduction.fail.cpp

@@ -0,0 +1,47 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-deduction-guides
+
+// template<class InputIterator>
+//   basic_string(InputIterator begin, InputIterator end,
+//   const Allocator& a = Allocator());
+
+// template<class charT,
+//          class traits,
+//          class Allocator = allocator<charT>
+//          >
+// basic_string(basic_string_view<charT, traits>,
+//                typename see below::size_type,
+//                typename see below::size_type,
+//                const Allocator& = Allocator())
+//   -> basic_string<charT, traits, Allocator>;
+//
+//  A size_type parameter type in a basic_string deduction guide refers to the size_type 
+//  member type of the type deduced by the deduction guide.
+//
+//  The deduction guide shall not participate in overload resolution if Allocator
+//  is a type that does not qualify as an allocator.
+
+
+#include <string>
+#include <string_view>
+#include <iterator>
+#include <cassert>
+#include <cstddef>
+
+int main()
+{
+    {
+    std::string_view sv = "12345678901234";
+    std::basic_string s1{sv, 0, 4, 23}; // expected-error {{no viable constructor or deduction guide for deduction of template arguments of 'basic_string'}}
+    }
+}

test/std/strings/basic.string/string.cons/string_view_size_size_deduction.pass.cpp

@@ -0,0 +1,99 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-deduction-guides
+
+// template<class InputIterator>
+//   basic_string(InputIterator begin, InputIterator end,
+//   const Allocator& a = Allocator());
+
+// template<class charT,
+//          class traits,
+//          class Allocator = allocator<charT>
+//          >
+// basic_string(basic_string_view<charT, traits>,
+//                typename see below::size_type,
+//                typename see below::size_type,
+//                const Allocator& = Allocator())
+//   -> basic_string<charT, traits, Allocator>;
+//
+//  A size_type parameter type in a basic_string deduction guide refers to the size_type 
+//  member type of the type deduced by the deduction guide.
+//
+//  The deduction guide shall not participate in overload resolution if Allocator
+//  is a type that does not qualify as an allocator.
+
+
+#include <string>
+#include <string_view>
+#include <iterator>
+#include <cassert>
+#include <cstddef>
+
+#include "test_macros.h"
+#include "test_allocator.h"
+#include "../input_iterator.h"
+#include "min_allocator.h"
+
+int main()
+{
+    {
+    std::string_view sv = "12345678901234";
+    std::basic_string s1{sv, 0, 4};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                      char>,  "");
+    static_assert(std::is_same_v<S::traits_type,    std::char_traits<char>>, "");
+    static_assert(std::is_same_v<S::allocator_type,   std::allocator<char>>, "");
+    assert(s1.size() == 4);
+    assert(s1.compare(0, s1.size(), sv.data(), s1.size()) == 0);
+    }
+
+    {
+    std::string_view sv = "12345678901234";
+    std::basic_string s1{sv, 0, 4, std::allocator<char>{}};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                      char>,  "");
+    static_assert(std::is_same_v<S::traits_type,    std::char_traits<char>>, "");
+    static_assert(std::is_same_v<S::allocator_type,   std::allocator<char>>, "");
+    assert(s1.size() == 4);
+    assert(s1.compare(0, s1.size(), sv.data(), s1.size()) == 0);
+    }
+    {
+    std::wstring_view sv = L"12345678901234";
+    std::basic_string s1{sv, 0, 4, test_allocator<wchar_t>{}};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                      wchar_t>,  "");
+    static_assert(std::is_same_v<S::traits_type,    std::char_traits<wchar_t>>, "");
+    static_assert(std::is_same_v<S::allocator_type,   test_allocator<wchar_t>>, "");
+    assert(s1.size() == 4);
+    assert(s1.compare(0, s1.size(), sv.data(), s1.size()) == 0);
+    }
+    {
+    std::u16string_view sv = u"12345678901234";
+    std::basic_string s1{sv, 0, 4, min_allocator<char16_t>{}};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                      char16_t>,  "");
+    static_assert(std::is_same_v<S::traits_type,    std::char_traits<char16_t>>, "");
+    static_assert(std::is_same_v<S::allocator_type,    min_allocator<char16_t>>, "");
+    assert(s1.size() == 4);
+    assert(s1.compare(0, s1.size(), sv.data(), s1.size()) == 0);
+    }
+    {
+    std::u32string_view sv = U"12345678901234";
+    std::basic_string s1{sv, 0, 4, explicit_allocator<char32_t>{}};
+    using S = decltype(s1); // what type did we get?
+    static_assert(std::is_same_v<S::value_type,                        char32_t>,  "");
+    static_assert(std::is_same_v<S::traits_type,      std::char_traits<char32_t>>, "");
+    static_assert(std::is_same_v<S::allocator_type, explicit_allocator<char32_t>>, "");
+    assert(s1.size() == 4);
+    assert(s1.compare(0, s1.size(), sv.data(), s1.size()) == 0);
+    }
+}