Function performOptionalSelector

tutorials/external/catch.hpp:1190–1194

    [obj release];
}
inline id performOptionalSelector( id obj, SEL sel ) {
    if( [obj respondsToSelector: sel] )
        return [obj performSelector: sel];
    return nil;
}
#define CATCH_UNSAFE_UNRETAINED
#define CATCH_ARC_STRONG
#else