Created attachment 221301 [details] testcase-templated-method.cpp Wrong (ccc is called with G<bool>, not G<CO>): > $ nm testcase-templated-method.o | grep ccc | c++filt > U void G<CO>::ccc<bool>(G const&<CO>) Correct with c++filt from devel/binutils: > $ nm testcase-templated-method.o | grep ccc | /usr/local/bin/c++filt > U void G<CO>::ccc<bool>(G<bool> const&) Correct with llbm's c++filt: > $ nm testcase-templated-method.o | grep ccc | /usr/local/llvm10/bin/llvm-cxxfilt > U void G<CO>::ccc<bool>(G<bool> const&)