Daniel Walker wrote: On Sat, Nov 6, 2010 at 7:53 PM, Peter Dimov <pdimov@pdimov.com> wrote:
void throw_bad_function_call() { throw bad_function_call(); }
function<void()> f( &throw_bad_function_call );
doesn't take up any additional space per type, unless of course the program never stores a function pointer into function<>.
This is a special case: all targets are function pointers of the same type, right?
No. It's enough for one of them to be.
On my system, the text segment grows by up to 14% when boost::function( &throw_bad_function_call ) is used for empty wrappers.
It's very uncommon for real code to not already contain the necessary instantiations or the equivalent of throw_bad_function_call itself. As soon as you put a function pointer into boost::function, you ought to get the instantiations; and as soon as you call it, you ought to get code that throws bad_function_call. Or I may be missing something.