https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68880
Bug ID: 68880 Summary: [4.9 Regression][Bisected to r202992] std::operator< overload ignored when using std::lower_bound Product: gcc Version: 5.3.0 Status: UNCONFIRMED Keywords: rejects-valid Severity: normal Priority: P3 Component: libstdc++ Assignee: unassigned at gcc dot gnu.org Reporter: david.ward at ll dot mit.edu CC: fdumont at gcc dot gnu.org Target Milestone: --- Created attachment 37018 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=37018&action=edit Preprocessed file Prior to r202992 the following compiles without any warning: #include <deque> #include <algorithm> namespace N { struct S { int x; int y; }; } namespace std { bool operator< (const N::S &lhs, const N::S &rhs) { return lhs.y < rhs.y; } } class C { public: void f() { std::deque<N::S> deq; N::S val; val.y = 10; std::deque<N::S>::iterator it = std::lower_bound(deq.begin(), deq.end(), val); } }; int main() { C obj; obj.f(); } Now it fails, as it no longer recognizes the std::operator< overload. The output below is from gcc 5.3.0, but I just checked that it is still broken in SVN trunk: # g++ -v -save-temps svn-r202992-regression.cpp Using built-in specs. COLLECT_GCC=g++ COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/lto-wrapper Target: x86_64-unknown-linux-gnu Configured with: /build/gcc/src/gcc-5.3.0/configure --prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=https://bugs.archlinux.org/ --enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++ --enable-shared --enable-threads=posix --enable-libmpx --with-system-zlib --with-isl --enable-__cxa_atexit --disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch --disable-libssp --enable-gnu-unique-object --enable-linker-build-id --enable-lto --enable-plugin --enable-install-libiberty --with-linker-hash-style=gnu --enable-gnu-indirect-function --disable-multilib --disable-werror --enable-checking=release Thread model: posix gcc version 5.3.0 (GCC) COLLECT_GCC_OPTIONS='-v' '-save-temps' '-shared-libgcc' '-mtune=generic' '-march=x86-64' /usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/cc1plus -E -quiet -v -D_GNU_SOURCE svn-r202992-regression.cpp -mtune=generic -march=x86-64 -fpch-preprocess -o svn-r202992-regression.ii ignoring nonexistent directory "/usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/../../../../x86_64-unknown-linux-gnu/include" #include "..." search starts here: #include <...> search starts here: /usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/../../../../include/c++/5.3.0 /usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/../../../../include/c++/5.3.0/x86_64-unknown-linux-gnu /usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/../../../../include/c++/5.3.0/backward /usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/include /usr/local/include /usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/include-fixed /usr/include End of search list. COLLECT_GCC_OPTIONS='-v' '-save-temps' '-shared-libgcc' '-mtune=generic' '-march=x86-64' /usr/lib/gcc/x86_64-unknown-linux-gnu/5.3.0/cc1plus -fpreprocessed svn-r202992-regression.ii -quiet -dumpbase svn-r202992-regression.cpp -mtune=generic -march=x86-64 -auxbase svn-r202992-regression -version -o svn-r202992-regression.s GNU C++ (GCC) version 5.3.0 (x86_64-unknown-linux-gnu) compiled by GNU C version 5.3.0, GMP version 6.1.0, MPFR version 3.1.3-p5, MPC version 1.0.3 warning: MPFR header version 3.1.3-p5 differs from library version 3.1.3-p4. GGC heuristics: --param ggc-min-expand=98 --param ggc-min-heapsize=127710 GNU C++ (GCC) version 5.3.0 (x86_64-unknown-linux-gnu) compiled by GNU C version 5.3.0, GMP version 6.1.0, MPFR version 3.1.3-p5, MPC version 1.0.3 warning: MPFR header version 3.1.3-p5 differs from library version 3.1.3-p4. GGC heuristics: --param ggc-min-expand=98 --param ggc-min-heapsize=127710 Compiler executable checksum: f5781c340dcd4c5ddaa4fbe9faee3243 In file included from /usr/include/c++/5.3.0/bits/stl_algobase.h:71:0, from /usr/include/c++/5.3.0/deque:60, from svn-r202992-regression.cpp:1: /usr/include/c++/5.3.0/bits/predefined_ops.h: In instantiation of ‘bool __gnu_cxx::__ops::_Iter_less_val::operator()(_Iterator, _Value&) const [with _Iterator = std::_Deque_iterator<N::S, N::S&, N::S*>; _Value = const N::S]’: /usr/include/c++/5.3.0/bits/stl_algobase.h:971:14: required from ‘_ForwardIterator std::__lower_bound(_ForwardIterator, _ForwardIterator, const _Tp&, _Compare) [with _ForwardIterator = std::_Deque_iterator<N::S, N::S&, N::S*>; _Tp = N::S; _Compare = __gnu_cxx::__ops::_Iter_less_val]’ /usr/include/c++/5.3.0/bits/stl_algobase.h:1005:32: required from ‘_ForwardIterator std::lower_bound(_ForwardIterator, _ForwardIterator, const _Tp&) [with _ForwardIterator = std::_Deque_iterator<N::S, N::S&, N::S*>; _Tp = N::S]’ svn-r202992-regression.cpp:34:55: required from here /usr/include/c++/5.3.0/bits/predefined_ops.h:55:22: error: no match for ‘operator<’ (operand types are ‘N::S’ and ‘const N::S’) { return *__it < __val; } ^ In file included from /usr/include/c++/5.3.0/bits/stl_algobase.h:67:0, from /usr/include/c++/5.3.0/deque:60, from svn-r202992-regression.cpp:1: /usr/include/c++/5.3.0/bits/stl_iterator.h:849:5: note: candidate: template<class _IteratorL, class _IteratorR, class _Container> bool __gnu_cxx::operator<(const __gnu_cxx::__normal_iterator<_IteratorL, _Container>&, const __gnu_cxx::__normal_iterator<_IteratorR, _Container>&) operator<(const __normal_iterator<_IteratorL, _Container>& __lhs, ^ /usr/include/c++/5.3.0/bits/stl_iterator.h:849:5: note: template argument deduction/substitution failed: In file included from /usr/include/c++/5.3.0/bits/stl_algobase.h:71:0, from /usr/include/c++/5.3.0/deque:60, from svn-r202992-regression.cpp:1: /usr/include/c++/5.3.0/bits/predefined_ops.h:55:22: note: ‘N::S’ is not derived from ‘const __gnu_cxx::__normal_iterator<_IteratorL, _Container>’ { return *__it < __val; } ^ In file included from /usr/include/c++/5.3.0/bits/stl_algobase.h:67:0, from /usr/include/c++/5.3.0/deque:60, from svn-r202992-regression.cpp:1: /usr/include/c++/5.3.0/bits/stl_iterator.h:856:5: note: candidate: template<class _Iterator, class _Container> bool __gnu_cxx::operator<(const __gnu_cxx::__normal_iterator<_Iterator, _Container>&, const __gnu_cxx::__normal_iterator<_Iterator, _Container>&) operator<(const __normal_iterator<_Iterator, _Container>& __lhs, ^ /usr/include/c++/5.3.0/bits/stl_iterator.h:856:5: note: template argument deduction/substitution failed: In file included from /usr/include/c++/5.3.0/bits/stl_algobase.h:71:0, from /usr/include/c++/5.3.0/deque:60, from svn-r202992-regression.cpp:1: /usr/include/c++/5.3.0/bits/predefined_ops.h:55:22: note: ‘N::S’ is not derived from ‘const __gnu_cxx::__normal_iterator<_Iterator, _Container>’ { return *__it < __val; } ^