https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67468
Bug ID: 67468 Summary: compiler changes template argument Product: gcc Version: 6.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: cas43 at cs dot stanford.edu Target Milestone: --- When compiled with: g++ -c prog.cpp -Q The compiler output contains "B<A<S>::x>" but the input contains "B<A<R>::x>". The compiler has replaced the template argument R with the template argument S. CODE: template<class T> struct A { const static int x=0; }; template<int d> struct B; template<class R,class S> class C { const static int x=A<R>::x<A<S>::x?A<R>::x:A<S>::x; }; template<class T,class R,class S> int Get_Block_At_Mask(const C<R,S>& c,B<A<R>::x>* b) { return 0; } COMPILER OUTPUT: int Get_Block_At_Mask(const C<R, S>&, B<A<S>::x>*) Analyzing compilation unit Performing interprocedural optimizations <*free_lang_data> <visibility> <build_ssa_passes> <opt_local_passes> <free-inline-summary> <whole-program> <inline>Assembling functions: Execution times (seconds) phase setup : 0.00 ( 0%) usr 0.00 ( 0%) sys 0.01 (100%) wall 1381 kB (80%) ggc TOTAL : 0.00 0.00 0.01 1734 kB Extra diagnostic checks enabled; compiler may run slowly. Configure with --enable-checking=release to disable checks. COMPILER VERSIONS TESTED: Using built-in specs. COLLECT_GCC=/home/craig/new-gcc/i-trunk/bin/g++ COLLECT_LTO_WRAPPER=/home/craig/new-gcc/i-trunk/libexec/gcc/x86_64-pc-linux-gnu/6.0.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: ../s-trunk/configure --prefix=/home/craig/new-gcc/i-trunk Thread model: posix gcc version 6.0.0 20150906 (experimental) (GCC) -- and -- g++-5 (Ubuntu 5.1.0-0ubuntu11~14.04.1) 5.1.0 Copyright (C) 2015 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.