Hi Sébastien, >May be gcc 4 just support inline functions for templates? (but why gcc 3.4 has no problem with that?) GCC 4 supports non-inline functions for templates for me, just fine. template <typename T> T NonInline(T input) { return input - 1; } template <typename T> inline T Inline(T input) { return input + 1; } int main() { int i = 10; i = NonInline(i); i = NonInline(i); i = NonInline(i); i = NonInline(i); int j = 10; j = Inline(j); j = Inline(j); j = Inline(j); j = Inline(j); } Sincerely, --Eljay