http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56760
--- Comment #2 from erik.thi...@thiele-hydraulik.de 2013-03-28 07:05:22 UTC --- You see attached two files. v1.cpp and v2.cpp g++ --version g++ (Debian 4.7.2-5) 4.7.2 Copyright (C) 2012 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. g++ -Wall v1.cpp /tmp/ccZAyNEb.o: In function `void func<seco::holder<int> >(seco::contain<seco::holder<int> > const&, nam::binbuffer&)': v1.cpp:(.text._Z4funcIN4seco6holderIiEEEvRKNS0_7containIT_EERN3nam9binbufferE[_Z4funcIN4seco6holderIiEEEvRKNS0_7containIT_EERN3nam9binbufferE]+0x16): undefined reference to `void func<seco::holder<int> >(seco::holder<int> const&, nam::binbuffer&)' collect2: error: ld returned 1 exit status g++ -Wall v2.cpp --> no errors in v1.cpp you see a commented out line with a template forward declaration. if you comment that in: g++ -Wall v1.cpp --> no errors The only difference between v1 and v2 is that in v2 you do not have the "nam" namespace.
