Is this expected to not compile with -fno-implicit-templates? ---%<--- $ cat test.cc #include <string> std::string test(int i) { std::string t; std::string s = "("; t = ""; for (int r = i; r; r>>=1) { if (r & 1) t = "1" + t; else t = "0" + t; } s += t; s += ")"; return s; } int main(int argc, char *argv[]) { std::string s = test(16); return 0; } $ g++ -fno-implicit-templates test.cc /tmp/ccai7t5T.o: In function `test(int)': test.cc:(.text+0x9d): undefined reference to `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > std::operator+<char, std::char_traits<char>, std::allocator<char> >(char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)' test.cc:(.text+0xd9): undefined reference to `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > std::operator+<char, std::char_traits<char>, std::allocator<char> >(char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)' collect2: error: ld returned 1 exit status ---%<--- I am trying to fix a package, but it is documented to require -fno-implicit-templates and instantiate templates in one of the sources, but it instantiates templates for its own types. Thanks, Paulo