Hi, Upto boost 1.33.x, I could compile my program with the gcc option -fno-exceptions. Since boost 1.34.0, this is no longer possible due to code changes in operator= in boost/function/function_template.hpp The following snippets fail to compile: Line 561-571: operator=(Functor BOOST_FUNCTION_TARGET_FIX(const &) f) { this->clear(); try { this->assign_to(f); } catch (...) { vtable = 0; throw; } return *this; } and lines 589-602: // Assignment from another BOOST_FUNCTION_FUNCTION BOOST_FUNCTION_FUNCTION& operator=(const BOOST_FUNCTION_FUNCTION& f) { if (&f == this) return *this; this->clear(); try { this->assign_to_own(f); } catch (...) { vtable = 0; throw; } return *this; } The 1.33.0 and older versions used swap() instead of this try / catch / throw construct. These versions also used the boost::throw_exception function instead of a plain throw. Any rationale for this decision ? Should some/all boost functions compile exception free as well ? I'm using -fno-exceptions on embedded systems. Peter -- Peter Soetens -- FMTC -- http://www.fmtc.be