From e46c1def523323eedfad1174fd2fabbece8f40cc Mon Sep 17 00:00:00 2001
From: Raphael Isemann <teemperor@gmail.com>
Date: Wed, 23 Sep 2020 10:03:42 +0200
Subject: [PATCH] Revert "[libc++] Implement LWG1203"
This reverts commit fdc41e11f9687a50c97e2a59663bf2d541ff5489. It causes the
libcxx/modules/stds_include.sh.cpp test to fail with:
libcxx/include/ostream:1039:45: error: no template named 'enable_if_t'; did you mean 'enable_if'?
template <class _Stream, class _Tp, class = enable_if_t<
Still investigating what's causing this and reverting in the meantime to get
the bots green again.
---
libcxx/include/istream | 26 ++++--------
libcxx/include/ostream | 26 +++++-------
.../istream.rvalue/not_istreamable.verify.cpp | 20 ---------
.../istream.rvalue/rvalue.pass.cpp | 41 +++++++------------
...rvalue.pass.cpp => CharT_pointer.pass.cpp} | 29 +++++--------
.../ostream.rvalue/not_ostreamable.verify.cpp | 19 ---------
libcxx/www/cxx2a_status.html | 2 +-
7 files changed, 45 insertions(+), 118 deletions(-)
delete mode 100644 libcxx/test/std/input.output/iostream.format/input.streams/istream.rvalue/not_istreamable.verify.cpp
rename libcxx/test/std/input.output/iostream.format/output.streams/ostream.rvalue/{rvalue.pass.cpp => CharT_pointer.pass.cpp} (71%)
delete mode 100644 libcxx/test/std/input.output/iostream.format/output.streams/ostream.rvalue/not_ostreamable.verify.cpp
diff --git a/libcxx/include/istream b/libcxx/include/istream
index 5145157aa42a..bfbe5f24728e 100644
--- a/libcxx/include/istream
+++ b/libcxx/include/istream
@@ -150,9 +150,9 @@ template <class charT, class traits>
basic_istream<charT,traits>&
ws(basic_istream<charT,traits>& is);
-// rvalue stream extraction
-template <class Stream, class T>
- Stream&& operator>>(Stream&& is, T&& x);
+template <class charT, class traits, class T>
+ basic_istream<charT, traits>&
+ operator>>(basic_istream<charT, traits>&& is, T& x);
} // std
@@ -1378,23 +1378,13 @@ ws(basic_istream<_CharT, _Traits>& __is)
#ifndef _LIBCPP_CXX03_LANG
-template <class _Stream, class _Tp, class = void>
-struct __is_istreamable : false_type { };
-
-template <class _Stream, class _Tp>
-struct __is_istreamable<_Stream, _Tp, decltype(
- _VSTD::declval<_Stream>() >> _VSTD::declval<_Tp>(), void()
-)> : true_type { };
-
-template <class _Stream, class _Tp, class = enable_if_t<
- _And<is_base_of<ios_base, _Stream>,
- __is_istreamable<_Stream&, _Tp&&>>::value
->>
-_LIBCPP_INLINE_VISIBILITY
-_Stream&& operator>>(_Stream&& __is, _Tp&& __x)
+template <class _CharT, class _Traits, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>&& __is, _Tp&& __x)
{
__is >> _VSTD::forward<_Tp>(__x);
- return _VSTD::move(__is);
+ return __is;
}
#endif // _LIBCPP_CXX03_LANG
diff --git a/libcxx/include/ostream b/libcxx/include/ostream
index fc0bf69e9d92..697732d54e6d 100644
--- a/libcxx/include/ostream
+++ b/libcxx/include/ostream
@@ -126,8 +126,9 @@ template <class charT, class traits>
basic_ostream<charT,traits>& flush(basic_ostream<charT,traits>& os);
// rvalue stream insertion
-template <class Stream, class T>
- Stream&& operator<<(Stream&& os, const T& x);
+template <class charT, class traits, class T>
+ basic_ostream<charT, traits>&
+ operator<<(basic_ostream<charT, traits>&& os, const T& x);
} // std
@@ -1027,20 +1028,15 @@ flush(basic_ostream<_CharT, _Traits>& __os)
#ifndef _LIBCPP_CXX03_LANG
-template <class _Stream, class _Tp, class = void>
-struct __is_ostreamable : false_type { };
-
template <class _Stream, class _Tp>
-struct __is_ostreamable<_Stream, _Tp, decltype(
- _VSTD::declval<_Stream>() << _VSTD::declval<_Tp>(), void()
-)> : true_type { };
-
-template <class _Stream, class _Tp, class = enable_if_t<
- _And<is_base_of<ios_base, _Stream>,
- __is_ostreamable<_Stream&, const _Tp&>>::value
->>
-_LIBCPP_INLINE_VISIBILITY
-_Stream&& operator<<(_Stream&& __os, const _Tp& __x)
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+ !is_lvalue_reference<_Stream>::value &&
+ is_base_of<ios_base, _Stream>::value,
+ _Stream&&
+>::type
+operator<<(_Stream&& __os, const _Tp& __x)
{
__os << __x;
return _VSTD::move(__os);
diff --git a/libcxx/test/std/input.output/iostream.format/input.streams/istream.rvalue/not_istreamable.verify.cpp b/libcxx/test/std/input.output/iostream.format/input.streams/istream.rvalue/not_istreamable.verify.cpp
deleted file mode 100644
index 1a03ed69b140..000000000000
--- a/libcxx/test/std/input.output/iostream.format/input.streams/istream.rvalue/not_istreamable.verify.cpp
+++ /dev/null
@@ -1,20 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++03
-
-// Make sure the rvalue overload of operator>> isn't part of the overload set
-// when the type is not input streamable from a lvalue stream.
-
-#include <istream>
-#include <utility>
-
-struct Foo { };
-
-using X = decltype(std::declval<std::istream>() >> std::declval<Foo&>()); // expected-error {{invalid operands to binary expression}}
-using Y = decltype(std::declval<std::istream>() >> std::declval<Foo>()); // expected-error {{invalid operands to binary expression}}
diff --git a/libcxx/test/std/input.output/iostream.format/input.streams/istream.rvalue/rvalue.pass.cpp b/libcxx/test/std/input.output/iostream.format/input.streams/istream.rvalue/rvalue.pass.cpp
index 70ada3a9239f..df65aed76dfd 100644
--- a/libcxx/test/std/input.output/iostream.format/input.streams/istream.rvalue/rvalue.pass.cpp
+++ b/libcxx/test/std/input.output/iostream.format/input.streams/istream.rvalue/rvalue.pass.cpp
@@ -10,8 +10,9 @@
// <istream>
-// template <class Stream, class T>
-// Stream&& operator>>(Stream&& is, T&& x);
+// template <class charT, class traits, class T>
+// basic_istream<charT, traits>&
+// operator>>(basic_istream<charT, traits>&& is, T&& x);
#include <istream>
#include <sstream>
@@ -43,44 +44,32 @@ public:
CharT* egptr() const {return base::egptr();}
};
-struct Int {
- int value;
- template <class CharT>
- friend void operator>>(std::basic_istream<CharT>& is, Int& self) {
- is >> self.value;
- }
-};
-struct A { };
+struct A{};
bool called = false;
-void operator>>(std::istream&, A&&) { called = true; }
+void operator>>(std::istream&, A&&){ called = true; }
int main(int, char**)
{
{
testbuf<char> sb(" 123");
- Int i = {0};
- std::istream is(&sb);
- std::istream&& result = (std::move(is) >> i);
- assert(&result == &is);
- assert(i.value == 123);
+ int i = 0;
+ std::istream(&sb) >> i;
+ assert(i == 123);
}
{
testbuf<wchar_t> sb(L" 123");
- Int i = {0};
- std::wistream is(&sb);
- std::wistream&& result = (std::move(is) >> i);
- assert(&result == &is);
- assert(i.value == 123);
+ int i = 0;
+ std::wistream(&sb) >> i;
+ assert(i == 123);
}
- {
- // test perfect forwarding
+ { // test perfect forwarding
assert(called == false);
std::istringstream ss;
- std::istringstream&& result = (std::move(ss) >> A{});
- assert(&result == &ss);
+ auto&& out = (std::move(ss) >> A{});
+ assert(&out == &ss);
assert(called);
}
- return 0;
+ return 0;
}
diff --git a/libcxx/test/std/input.output/iostream.format/output.streams/ostream.rvalue/rvalue.pass.cpp b/libcxx/test/std/input.output/iostream.format/output.streams/ostream.rvalue/CharT_pointer.pass.cpp
similarity index 71%
rename from libcxx/test/std/input.output/iostream.format/output.streams/ostream.rvalue/rvalue.pass.cpp
rename to libcxx/test/std/input.output/iostream.format/output.streams/ostream.rvalue/CharT_pointer.pass.cpp
index 99e70c425169..87ab6bae3907 100644
--- a/libcxx/test/std/input.output/iostream.format/output.streams/ostream.rvalue/rvalue.pass.cpp
+++ b/libcxx/test/std/input.output/iostream.format/output.streams/ostream.rvalue/CharT_pointer.pass.cpp
@@ -10,8 +10,12 @@
// <ostream>
-// template <class Stream, class T>
-// Stream&& operator<<(Stream&& os, const T& x);
+// template <class charT, class traits = char_traits<charT> >
+// class basic_ostream;
+
+// template <class charT, class traits, class T>
+// basic_ostream<charT, traits>&
+// operator<<(basic_ostream<charT, traits>&& os, const T& x);
#include <ostream>
#include <cassert>
@@ -51,32 +55,19 @@ protected:
}
};
-struct Int {
- int value;
- template <class CharT>
- friend void operator<<(std::basic_ostream<CharT>& os, Int const& self) {
- os << self.value;
- }
-};
int main(int, char**)
{
{
testbuf<char> sb;
- std::ostream os(&sb);
- Int const i = {123};
- std::ostream&& result = (std::move(os) << i);
- assert(&result == &os);
- assert(sb.str() == "123");
+ std::ostream(&sb) << "testing...";
+ assert(sb.str() == "testing...");
}
{
testbuf<wchar_t> sb;
- std::wostream os(&sb);
- Int const i = {123};
- std::wostream&& result = (std::move(os) << i);
- assert(&result == &os);
+ std::wostream(&sb) << L"123";
assert(sb.str() == L"123");
}
- return 0;
+ return 0;
}
diff --git a/libcxx/test/std/input.output/iostream.format/output.streams/ostream.rvalue/not_ostreamable.verify.cpp b/libcxx/test/std/input.output/iostream.format/output.streams/ostream.rvalue/not_ostreamable.verify.cpp
deleted file mode 100644
index 7ca36c562261..000000000000
--- a/libcxx/test/std/input.output/iostream.format/output.streams/ostream.rvalue/not_ostreamable.verify.cpp
+++ /dev/null
@@ -1,19 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++03
-
-// Make sure the rvalue overload of operator<< isn't part of the overload set
-// when the type is not output streamable into a lvalue stream.
-
-#include <ostream>
-#include <utility>
-
-struct Foo { };
-
-using X = decltype(std::declval<std::ostream>() << std::declval<Foo const&>()); // expected-error {{invalid operands to binary expression}}
diff --git a/libcxx/www/cxx2a_status.html b/libcxx/www/cxx2a_status.html
index 25d9f24a001f..d1bf4744b495 100644
--- a/libcxx/www/cxx2a_status.html
+++ b/libcxx/www/cxx2a_status.html
@@ -468,7 +468,7 @@
<tr><td><a href="https://wg21.link/LWG3149">3149</a></td><td><tt>DefaultConstructible</tt> should require default initialization</td><td>Belfast</td><td></td></tr>
<tr><td></td><td></td><td></td><td></td></tr> -->
- <tr><td><a href="https://wg21.link/LWG1203">1203</a></td><td>More useful rvalue stream insertion</td><td>Prague</td><td>12.0</td></tr>
+ <tr><td><a href="https://wg21.link/LWG1203">1203</a></td><td>More useful rvalue stream insertion</td><td>Prague</td><td></td></tr>
<tr><td><a href="https://wg21.link/LWG2859">2859</a></td><td>Definition of <em>reachable</em> in [ptr.launder] misses pointer arithmetic from pointer-interconvertible object</td><td>Prague</td><td></td></tr>
<tr><td><a href="https://wg21.link/LWG3018">3018</a></td><td><tt>shared_ptr</tt> of function type</td><td>Prague</td><td></td></tr>
<tr><td><a href="https://wg21.link/LWG3050">3050</a></td><td>Conversion specification problem in <tt>chrono::duration</tt> constructor</td><td>Prague</td><td></td></tr>