c++ - Catching exceptions for specific base members during construction -

i'm aware, given class foo base class base can write

foo(/*real code has parameters here*/) try :     base(), /*real code has parameters here*/    anothermember(somefunction(/*some parameters here*/)) { } catch (...){ } 

but there syntax can use put try catch block around anothermember opposed entire base member list , constructor body?

(note anothermember const type needs in initialiser list)

doing doesn't quite make sense anothermember initialises function put try..catch in function. i'm assuming has copy-constructor doesn't throw , 1 might throw takes parameters , somefunction invokes one.

what want if anothermember fails construct properly?

your obvious alternative wrap anothermember in kind of smart-pointer, possibly making "nullable" if failed initialise. if created own special object contain message of exception thrown .

struct anothertypewrapper {     std::unique_ptr< anothertype > ptr;     std::string errormsg;      anothertypewrapper( args&& args... ) // ok not variadic     {        try        {           ptr.reset( new anothertype( std::forward(args) ) ); // or whatever syntax        }        catch( std::exception const& err )        {           errormsg = err.what();        }     } }; 

something that.