[libstdc++-v3][C++14] Implement N3654 - Quoted Strings
Ed Smith-Rowland
3dw4rd@verizon.net
Thu Jun 6 14:55:00 GMT 2013
On 06/05/2013 04:01 PM, Jonathan Wakely wrote:
> On 5 June 2013 20:18, Ed Smith-Rowland wrote:
>> Greetings,
>> This patch implements quoted string manipulators for C++14.
>>
>> 27.7.6 - Quoted manipulators [quoted.manip].
>>
>> The idea is to allow round trip insert and extract of strings with spaces.
>>
>> std::stringstream ss;
>> std::string original = "thing1 thing1";
>> std::string round_trip;
>> ss << std::quoted(original);
>> ss >> std::quoted(round_trip);
>> assert( original == round_trip );
>>
>> Builds and tests clean on x86-64-linux.
> As I suggested for your literals patch, couldn't the test for:
> #if __cplusplus > 201103L
> go inside the existing one?
>
> i.e.
>
> #if __cplusplus >= 201103L
> [...]
> #if __cplusplus > 201103L
> [...]
> #endif
> #endif
Certainly. I forgot that in the last literals patch. I'll fix that
after I finish this one. (I just noticed junk comments in the testcases
for literals also).
>
>
> _Quoted_string appears to do two copies of the string, one for the
> constructor argument and one for the member variable, do they
> definitely get elided?
I looks that way. But all used of the template parm String are either
references or pointers so these operations should be efficient.
_Quoted_string should be used as a non-owning string thing.
>
> The members of _Quoted_string should be named _M_xxx not __xxx, to
> follow the coding style guidelines.
Done.
>
> What is __delim2 for?
>
> What if the first extraction in the operator>> fails, is doing
> __is.unget() the right thing to do?
Thanks. I'll return with __is rather than attempting to continue reading.
>
> You could simplify the quoted() overloads by using auto return type
> deduction, is it an intentional choice not to use that?
For some reason I forgot about auto return type in C++14. It sure
cleans things up nicely. Done.
Rebuilt and retested on x86_64
-------------- next part --------------
2013-06-05 Ed Smith-Rowland <3dw4rd@verizon.net>
Implement N3654 - Quoted Strings Library Proposal
* include/std/iomanip: Add quoted(String, Char delim, Char escape)
manipulators and supporting machinery in c++1y mode.
* testsuite/27_io/manipulators/standard/char/quoted.cc: New.
* testsuite/27_io/manipulators/standard/wchar_t/quoted.cc: New.
-------------- next part --------------
Index: include/std/iomanip
===================================================================
--- include/std/iomanip (revision 199730)
+++ include/std/iomanip (working copy)
@@ -334,8 +334,157 @@
return __os;
}
-#endif
+#if __cplusplus > 201103L
+ namespace __detail {
+
+ /**
+ * @brief Struct for delimited strings.
+ * The left and right delimiters can be different.
+ */
+ template<typename _String, typename _CharT>
+ struct _Quoted_string
+ {
+ _Quoted_string(_String __str, _CharT __del, _CharT __esc)
+ : _M_string(__str), _M_delim{__del}, _M_escape{__esc}
+ { }
+
+ _Quoted_string&
+ operator=(_Quoted_string&) = delete;
+
+ _String _M_string;
+ _CharT _M_delim;
+ _CharT _M_escape;
+ };
+
+ /**
+ * @brief Inserter for delimited strings.
+ * The left and right delimiters can be different.
+ */
+ template<typename _CharT, typename _Traits>
+ auto&
+ operator<<(std::basic_ostream<_CharT, _Traits>& __os,
+ const _Quoted_string<const _CharT*, _CharT>& __str)
+ {
+ __os << __str._M_delim;
+ for (const _CharT* __c = __str._M_string; *__c; ++__c)
+ {
+ if (*__c == __str._M_delim || *__c == __str._M_escape)
+ __os << __str._M_escape;
+ __os << *__c;
+ }
+ __os << __str._M_delim;
+
+ return __os;
+ }
+
+ /**
+ * @brief Inserter for delimited strings.
+ * The left and right delimiters can be different.
+ */
+ template<typename _CharT, typename _Traits, typename _String>
+ auto&
+ operator<<(std::basic_ostream<_CharT, _Traits>& __os,
+ const _Quoted_string<_String, _CharT>& __str)
+ {
+ __os << __str._M_delim;
+ for (auto& __c : __str._M_string)
+ {
+ if (__c == __str._M_delim || __c == __str._M_escape)
+ __os << __str._M_escape;
+ __os << __c;
+ }
+ __os << __str._M_delim;
+
+ return __os;
+ }
+
+ /**
+ * @brief Extractor for delimited strings.
+ * The left and right delimiters can be different.
+ */
+ template<typename _CharT, typename _Traits, typename _Alloc>
+ auto&
+ operator>>(std::basic_istream<_CharT, _Traits>& __is,
+ const _Quoted_string<basic_string<_CharT, _Traits, _Alloc>&,
+ _CharT>& __str)
+ {
+ __str._M_string.clear();
+
+ _CharT __c;
+ __is >> __c;
+ if (!__is.good())
+ return __is;
+ if (__c != __str._M_delim)
+ {
+ __is.unget();
+ __is >> __str._M_string;
+ return __is;
+ }
+ std::ios_base::fmtflags __flags
+ = __is.flags(__is.flags() & ~std::ios_base::skipws);
+ do
+ {
+ __is >> __c;
+ if (!__is.good())
+ break;
+ if (__c == __str._M_escape)
+ {
+ __is >> __c;
+ if (!__is.good())
+ break;
+ }
+ else if (__c == __str._M_delim)
+ break;
+ __str._M_string += __c;
+ }
+ while (true);
+ __is.setf(__flags);
+
+ return __is;
+ }
+
+ } // namespace __detail
+
+ /**
+ * @brief Manipulator for quoted strings.
+ * @param __str String to quote.
+ * @param __delim Character to quote string with.
+ * @param __escape Escape character to escape itself or quote character.
+ */
+ template<typename _CharT>
+ inline auto
+ quoted(const _CharT* __string,
+ _CharT __delim = _CharT('"'), _CharT __escape = _CharT('\\'))
+ {
+ return __detail::_Quoted_string<const _CharT*, _CharT>(__string, __delim,
+ __escape);
+ }
+
+ template<typename _CharT, typename _Traits, typename _Alloc>
+ inline auto
+ quoted(const basic_string<_CharT, _Traits, _Alloc>& __string,
+ _CharT __delim = _CharT('"'), _CharT __escape = _CharT('\\'))
+ {
+ return __detail::_Quoted_string<
+ const basic_string<_CharT, _Traits, _Alloc>&, _CharT>(
+ __string, __delim, __escape);
+ }
+
+ template<typename _CharT, typename _Traits, typename _Alloc>
+ inline auto
+ quoted(basic_string<_CharT, _Traits, _Alloc>& __string,
+ _CharT __delim = _CharT('"'), _CharT __escape = _CharT('\\'))
+ {
+ return __detail::_Quoted_string<
+ basic_string<_CharT, _Traits, _Alloc>&, _CharT>(
+ __string, __delim, __escape);
+ }
+
+#endif // __cplusplus > 201103L
+
+#endif // __cplusplus >= 201103L
+
// Inhibit implicit instantiations for required instantiations,
// which are defined via explicit instantiations elsewhere.
// NB: This syntax is a GNU extension.
Index: testsuite/27_io/manipulators/standard/char/quoted.cc
===================================================================
--- testsuite/27_io/manipulators/standard/char/quoted.cc (revision 0)
+++ testsuite/27_io/manipulators/standard/char/quoted.cc (working copy)
@@ -0,0 +1,75 @@
+// { dg-do run }
+// { dg-options "-std=gnu++1y" }
+
+// Copyright (C) 2013 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/>.
+
+// 27.7.6 - Quoted manipulators [quoted.manip]
+
+#include <string>
+#include <sstream>
+#include <iomanip>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+ bool test [[gnu::unused]] = true;
+ std::stringstream ss;
+ std::string original = "foolish me";
+ std::string round_trip;
+ ss << std::quoted(original);
+ ss >> std::quoted(round_trip);
+ VERIFY( original == round_trip );
+}
+
+void
+test02()
+{
+ // Test skipws correctness.
+ bool test [[gnu::unused]] = true;
+ std::stringstream ss;
+ ss << std::quoted("Hello Goodbye") << ' ' << 1 << ' ' << 2;
+ std::string song;
+ int thing1, thing2;
+ ss >> std::quoted(song) >> thing1 >> thing2;
+ VERIFY( song == "Hello Goodbye" );
+ VERIFY( thing1 == 1 );
+ VERIFY( thing2 == 2 );
+}
+
+void
+test03()
+{
+ // Test read of unquoted string.
+ bool test [[gnu::unused]] = true;
+ std::stringstream ss;
+ ss << "Alpha Omega";
+ std::string testit;
+ ss >> std::quoted(testit);
+ VERIFY( testit == "Alpha" );
+}
+
+int
+main()
+{
+ test01();
+ test02();
+ test03();
+
+ return 0;
+}
Index: testsuite/27_io/manipulators/standard/wchar_t/quoted.cc
===================================================================
--- testsuite/27_io/manipulators/standard/wchar_t/quoted.cc (revision 0)
+++ testsuite/27_io/manipulators/standard/wchar_t/quoted.cc (working copy)
@@ -0,0 +1,76 @@
+// { dg-do run }
+// { dg-options "-std=gnu++1y" }
+
+// Copyright (C) 2013 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/>.
+
+// 27.7.6 - Quoted manipulators [quoted.manip]
+
+#include <string>
+#include <sstream>
+#include <iomanip>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+ // Basic test from paper.
+ bool test [[gnu::unused]] = true;
+ std::wstringstream ss;
+ std::wstring original = L"foolish me";
+ std::wstring round_trip;
+ ss << std::quoted(original);
+ ss >> std::quoted(round_trip);
+ VERIFY( original == round_trip );
+}
+
+void
+test02()
+{
+ // Test skipws correctness.
+ bool test [[gnu::unused]] = true;
+ std::wstringstream ss;
+ ss << std::quoted(L"Hello Goodbye") << L' ' << 1 << L' ' << 2;
+ std::wstring song;
+ int thing1, thing2;
+ ss >> std::quoted(song) >> thing1 >> thing2;
+ VERIFY( song == L"Hello Goodbye" );
+ VERIFY( thing1 == 1 );
+ VERIFY( thing2 == 2 );
+}
+
+void
+test03()
+{
+ // Test read of unquoted string.
+ bool test [[gnu::unused]] = true;
+ std::wstringstream ss;
+ ss << L"Alpha Omega";
+ std::wstring testit;
+ ss >> std::quoted(testit);
+ VERIFY( testit == L"Alpha" );
+}
+
+int
+main()
+{
+ test01();
+ test02();
+ test03();
+
+ return 0;
+}
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