https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96830
Oliver Schönrock <oschonrock at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |oschonrock at gmail dot com --- Comment #7 from Oliver Schönrock <oschonrock at gmail dot com> --- It appears gcc's failure to "complain about redeclaration with inconsistent requires clause " might be hiding a small bug in libstdc++: https://godbolt.org/z/vxsY6oohM clang-trunk reports: /opt/compiler-explorer/gcc-snapshot/lib/gcc/x86_64-linux-gnu/13.0.0/../../../../include/c++/13.0.0/ranges:6098:14: error: requires clause differs in template redeclaration requires forward_range<_Vp> ^ /opt/compiler-explorer/gcc-snapshot/lib/gcc/x86_64-linux-gnu/13.0.0/../../../../include/c++/13.0.0/ranges:5797:14: note: previous template declaration is here requires input_range<_Vp> whereas gcc silently swallows the inconsistency?