Hello. I know the GCC C++ compiler can inline often-called functions automatically for performance reasons. I have to set the option -O3 for that. OK, but does it do inlining even across libraries? Say, I have a class like that: class Test { public: Test(); ~Test(); void called_very_often(); }; Test::Test() { } Test::~Test() { } void Test::called_very_often() { // one or two statements are placed here } This class is compiled into a static library called Test.lib or libtest.a. When I have a C++-Code like this: int main(int argc, char** argv) { Test * t = new Test(); [...] t->called_very_often(); [...] delete t; } When compiled with -O3, are there chances that the GCC C++ compiler will inline the member method called_very_often() of library class Test in main() even though it's compiled externally and called via a pointer? If not, what could I do to force that? Many Thanks! :) Best Regards Chester Kollschen