- perform:(SEL)aSelector
{
if (aSelector)
return objc_msgSend(self, aSelector);
else
return [self error:_errBadSel, sel_getName(_cmd), aSelector];
}
- perform:(SEL)aSelector with:anObject
{
if (aSelector)
return objc_msgSend(self, aSelector, anObject);
else
return [self error:_errBadSel, sel_getName(_cmd), aSelector];
}
- perform:(SEL)aSelector with:obj1 with:obj2
{
if (aSelector)
return objc_msgSend(self, aSelector, obj1, obj2);
else
return [self error:_errBadSel, sel_getName(_cmd), aSelector];
}
https://opensource.apple.com/source/objc4/objc4-493.9/runtime/