The standard requires overloads of std::to_chars for char and (un)signed
integer types. This means that our constrained function template is
non-conforming, because the difference is observable when using types
that convert to an integer (e.g. wchar_t, which promotes).
As well as defining the deleted bool overload for LWG 3266, replace the
constrained function template with overloads for each type.
* include/std/charconv (to_chars): Rename to __to_chars_i. Define
non-template overloads for each signed and unsigned integer type and
char. Define deleted overload for bool (LWG 3266).
* testsuite/20_util/to_chars/1_neg.cc: Remove.
* testsuite/20_util/to_chars/3.cc: New test.
* testsuite/20_util/to_chars/lwg3266.cc: New test.
Tested x86_64-linux, committed to trunk.
commit 6426125ff2dd91183ab94ec1c0fad83cd0f67104
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Tue Sep 10 08:50:01 2019 +0100
LWG 3266. to_chars(bool) should be deleted
The standard requires overloads of std::to_chars for char and (un)signed
integer types. This means that our constrained function template is
non-conforming, because the difference is observable when using types
that convert to an integer (e.g. wchar_t, which promotes).
As well as defining the deleted bool overload for LWG 3266, replace the
constrained function template with overloads for each type.
* include/std/charconv (to_chars): Rename to __to_chars_i. Define
non-template overloads for each signed and unsigned integer type and
char. Define deleted overload for bool (LWG 3266).
* testsuite/20_util/to_chars/1_neg.cc: Remove.
* testsuite/20_util/to_chars/3.cc: New test.
* testsuite/20_util/to_chars/lwg3266.cc: New test.
diff --git a/libstdc++-v3/include/std/charconv
b/libstdc++-v3/include/std/charconv
index ceefa3b6778..65f183f61f4 100644
--- a/libstdc++-v3/include/std/charconv
+++ b/libstdc++-v3/include/std/charconv
@@ -305,7 +305,7 @@ namespace __detail
template<typename _Tp>
__detail::__integer_to_chars_result_type<_Tp>
- to_chars(char* __first, char* __last, _Tp __value, int __base = 10)
+ __to_chars_i(char* __first, char* __last, _Tp __value, int __base = 10)
{
__glibcxx_assert(2 <= __base && __base <= 36);
@@ -341,6 +341,43 @@ namespace __detail
}
}
+#define _GLIBCXX_TO_CHARS(T) \
+ inline to_chars_result \
+ to_chars(char* __first, char* __last, T __value, int __base = 10) \
+ { return std::__to_chars_i<T>(__first, __last, __value, __base); }
+_GLIBCXX_TO_CHARS(char)
+_GLIBCXX_TO_CHARS(signed char)
+_GLIBCXX_TO_CHARS(unsigned char)
+_GLIBCXX_TO_CHARS(signed short)
+_GLIBCXX_TO_CHARS(unsigned short)
+_GLIBCXX_TO_CHARS(signed int)
+_GLIBCXX_TO_CHARS(unsigned int)
+_GLIBCXX_TO_CHARS(signed long)
+_GLIBCXX_TO_CHARS(unsigned long)
+_GLIBCXX_TO_CHARS(signed long long)
+_GLIBCXX_TO_CHARS(unsigned long long)
+#if defined(__GLIBCXX_TYPE_INT_N_0)
+_GLIBCXX_TO_CHARS(signed __GLIBCXX_TYPE_INT_N_0)
+_GLIBCXX_TO_CHARS(unsigned __GLIBCXX_TYPE_INT_N_0)
+#endif
+#if defined(__GLIBCXX_TYPE_INT_N_1)
+_GLIBCXX_TO_CHARS(signed __GLIBCXX_TYPE_INT_N_1)
+_GLIBCXX_TO_CHARS(unsigned __GLIBCXX_TYPE_INT_N_1)
+#endif
+#if defined(__GLIBCXX_TYPE_INT_N_2)
+_GLIBCXX_TO_CHARS(signed __GLIBCXX_TYPE_INT_N_2)
+_GLIBCXX_TO_CHARS(unsigned __GLIBCXX_TYPE_INT_N_2)
+#endif
+#if defined(__GLIBCXX_TYPE_INT_N_3)
+_GLIBCXX_TO_CHARS(signed __GLIBCXX_TYPE_INT_N_3)
+_GLIBCXX_TO_CHARS(unsigned __GLIBCXX_TYPE_INT_N_3)
+#endif
+#undef _GLIBCXX_TO_CHARS
+
+ // _GLIBCXX_RESOLVE_LIB_DEFECTS
+ // 3266. to_chars(bool) should be deleted
+ to_chars_result to_chars(char*, char*, bool, int = 10) = delete;
+
namespace __detail
{
template<typename _Tp>
diff --git a/libstdc++-v3/testsuite/20_util/to_chars/3.cc
b/libstdc++-v3/testsuite/20_util/to_chars/3.cc
new file mode 100644
index 00000000000..f8372fd7013
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/to_chars/3.cc
@@ -0,0 +1,60 @@
+// Copyright (C) 2019 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++17" }
+// { dg-do run { target c++17 } }
+// { dg-require-string-conversions "" }
+
+#include <charconv>
+#include <string_view>
+#include <testsuite_hooks.h>
+
+template<typename C>
+bool
+check_to_chars(C val)
+{
+ using std::string_view;
+
+ char buf1[32], buf2[32], buf3[32];
+ std::to_chars_result r1 = std::to_chars(buf1, buf1+sizeof(buf1), val);
+ if (r1.ec != std::errc{})
+ return false;
+ std::to_chars_result r2 = std::to_chars(buf2, buf2+sizeof(buf2), val, 10);
+ if (r2.ec != std::errc{})
+ return false;
+ if (string_view(buf1, r1.ptr - buf1) != string_view(buf2, r2.ptr - buf2))
+ return false;
+ std::to_chars_result r3 = std::to_chars(buf3, buf3+sizeof(buf3), (long)val);
+ if (string_view(buf1, r1.ptr - buf1) != string_view(buf3, r3.ptr - buf3))
+ return false;
+ return true;
+}
+
+void
+test01()
+{
+ VERIFY( check_to_chars(u'\x21') );
+ VERIFY( check_to_chars(U'\x21') );
+#if _GLIBCXX_USE_WCHAR_T
+ VERIFY( check_to_chars(L'\x21') );
+#endif
+}
+
+int main()
+{
+ test01();
+}
diff --git a/libstdc++-v3/testsuite/20_util/to_chars/1_neg.cc
b/libstdc++-v3/testsuite/20_util/to_chars/lwg3266.cc
similarity index 60%
rename from libstdc++-v3/testsuite/20_util/to_chars/1_neg.cc
rename to libstdc++-v3/testsuite/20_util/to_chars/lwg3266.cc
+++ b/libstdc++-v3/testsuite/20_util/to_chars/lwg3266.cc
@@ -1,4 +1,4 @@
-// Copyright (C) 2017-2019 Free Software Foundation, Inc.
+// Copyright (C) 2019 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
@@ -23,15 +23,8 @@
void
test01(char* first, char* last)
{
-#if _GLIBCXX_USE_WCHAR_T
- std::to_chars(first, last, L'\x1'); // { dg-error "no matching" }
- std::to_chars(first, last, L'\x1', 10); // { dg-error "no matching" }
-#endif
-
- std::to_chars(first, last, u'\x1'); // { dg-error "no matching" }
- std::to_chars(first, last, u'\x1', 10); // { dg-error "no matching" }
- std::to_chars(first, last, U'\x1'); // { dg-error "no matching" }
- std::to_chars(first, last, U'\x1', 10); // { dg-error "no matching" }
+ // LWG 3266. to_chars(bool) should be deleted
+ char buf;
+ std::to_chars(&buf, &buf + 1, true); // { dg-error "deleted function" }
+ std::to_chars(&buf, &buf + 1, false, 10); // { dg-error "deleted function" }
}
-
-// { dg-prune-output "enable_if" }
