From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 24451 invoked by alias); 30 Mar 2011 03:19:08 -0000 Received: (qmail 24442 invoked by uid 22791); 30 Mar 2011 03:19:07 -0000 X-SWARE-Spam-Status: No, hits=-2.7 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00,TW_CX,TW_DC,TW_JL X-Spam-Check-By: sourceware.org Received: from localhost (HELO gcc.gnu.org) (127.0.0.1) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 30 Mar 2011 03:19:03 +0000 From: "tinlyx at gmail dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/48350] New: make_tuple() on empty tuples does not compile X-Bugzilla-Reason: CC X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: c++ X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: tinlyx at gmail dot com X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: Message-ID: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Date: Wed, 30 Mar 2011 05:33:00 -0000 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2011-03/txt/msg03121.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48350 Summary: make_tuple() on empty tuples does not compile Product: gcc Version: 4.5.2 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ AssignedTo: unassigned@gcc.gnu.org ReportedBy: tinlyx@gmail.com Created attachment 23810 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23810 the example g++ 4.5.2 cannot create a unary tuple that contains an empty tuple (i.e. tuple<>() ) as the content. Minimal code example is as follows: //a.cpp #include using namespace std; int main() { auto te = make_tuple(); auto tte = make_tuple(te); return 0; } //// Compiling the above generates an error about invalid static_cast from type 'std::tuple<>' to type 'const std::_Tuple_impl<0u>&' Detailed compiler output is below: $ gcc -v -save-temps -std=c++0x a.cpp Using built-in specs. COLLECT_GCC=C:\MinGW\bin\gcc.exe COLLECT_LTO_WRAPPER=c:/mingw/bin/../libexec/gcc/mingw32/4.5.2/lto-wrapper.exe Target: mingw32 Configured with: ../gcc-4.5.2/configure --enable-languages=c,c++,ada,fortran,obj c,obj-c++ --disable-sjlj-exceptions --with-dwarf2 --enable-shared --enable-libgo mp --disable-win32-registry --enable-libstdcxx-debug --enable-version-specific-r untime-libs --disable-werror --build=mingw32 --prefix=/mingw Thread model: win32 gcc version 4.5.2 (GCC) COLLECT_GCC_OPTIONS='-v' '-save-temps' '-std=c++0x' '-mtune=i386' '-march=i386' c:/mingw/bin/../libexec/gcc/mingw32/4.5.2/cc1plus.exe -E -quiet -v -iprefix c:\ mingw\bin\../lib/gcc/mingw32/4.5.2/ a.cpp -mtune=i386 -march=i386 -std=c++0x -fp ch-preprocess -o a.ii ignoring nonexistent directory "c:\mingw\bin\../lib/gcc/mingw32/4.5.2/../../../. ./mingw32/include" ignoring duplicate directory "c:/mingw/lib/gcc/../../lib/gcc/mingw32/4.5.2/inclu de/c++" ignoring duplicate directory "c:/mingw/lib/gcc/../../lib/gcc/mingw32/4.5.2/inclu de/c++/mingw32" ignoring duplicate directory "c:/mingw/lib/gcc/../../lib/gcc/mingw32/4.5.2/inclu de/c++/backward" ignoring duplicate directory "/mingw/lib/gcc/mingw32/4.5.2/../../../../include" ignoring duplicate directory "c:/mingw/lib/gcc/../../include" ignoring duplicate directory "c:/mingw/lib/gcc/../../lib/gcc/mingw32/4.5.2/inclu de" ignoring duplicate directory "c:/mingw/lib/gcc/../../lib/gcc/mingw32/4.5.2/inclu de-fixed" ignoring nonexistent directory "c:/mingw/lib/gcc/../../lib/gcc/mingw32/4.5.2/../ ../../../mingw32/include" ignoring duplicate directory "/mingw/include" #include "..." search starts here: #include <...> search starts here: c:\mingw\bin\../lib/gcc/mingw32/4.5.2/include/c++ c:\mingw\bin\../lib/gcc/mingw32/4.5.2/include/c++/mingw32 c:\mingw\bin\../lib/gcc/mingw32/4.5.2/include/c++/backward c:\mingw\bin\../lib/gcc/mingw32/4.5.2/../../../../include c:\mingw\bin\../lib/gcc/mingw32/4.5.2/include c:\mingw\bin\../lib/gcc/mingw32/4.5.2/include-fixed End of search list. COLLECT_GCC_OPTIONS='-v' '-save-temps' '-std=c++0x' '-mtune=i386' '-march=i386' c:/mingw/bin/../libexec/gcc/mingw32/4.5.2/cc1plus.exe -fpreprocessed a.ii -quie t -dumpbase a.cpp -mtune=i386 -march=i386 -auxbase a -std=c++0x -version -o a.s GNU C++ (GCC) version 4.5.2 (mingw32) compiled by GNU C version 4.5.2, GMP version 5.0.1, MPFR version 2.4.1, MPC version 0.8.1 GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 GNU C++ (GCC) version 4.5.2 (mingw32) compiled by GNU C version 4.5.2, GMP version 5.0.1, MPFR version 2.4.1, MPC version 0.8.1 GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 Compiler executable checksum: bba7c68567cab1560329ee702fa8a945 In file included from a.cpp:1:0: c:\mingw\bin\../lib/gcc/mingw32/4.5.2/include/c++/tuple: In constructor 'std::tu ple<_Elements>::tuple(std::tuple<_UElements ...>&) [with _UElements = {}, _Eleme nts = {std::tuple<>}]': c:\mingw\bin\../lib/gcc/mingw32/4.5.2/include/c++/tuple:551:62: instantiated f rom 'std::tuple::__type ...> std::mak e_tuple(_Elements&& ...) [with _Elements = {std::tuple<>&}, typename std::__deca y_and_strip<_Elements>::__type = ]' a.cpp:6:27: instantiated from here c:\mingw\bin\../lib/gcc/mingw32/4.5.2/include/c++/tuple:259:70: error: invalid s tatic_cast from type 'std::tuple<>' to type 'const std::_Tuple_impl<0u>&'