Hey, thanks for looking into this. I guess the reason this hasn't come up before is that our styleguide explicitly disallows function overloading ( https://google.github.io/styleguide/cppguide.html#Function_Overloading)
However, I think it's reasonable to support other styles here as well. Have you considered contributing a patch? best -jochen On Thu, Jan 28, 2016 at 2:28 AM <xax...@gmail.com> wrote: > or perhaps the template on the constructor isn't even necessary? > > http://ideone.com/MXwvp9 > > shows the same behavior. > > V8_INLINE Local(T* that) > : val_(that) {} > V8_INLINE static Local<T> New(Isolate* isolate, T* that); > T* val_; > > On Wednesday, January 27, 2016 at 5:16:54 PM UTC-8, xax...@gmail.com > wrote: >> >> I think I simply had the parameters to is_convertible backwards in my >> first post: >> >> template <class S, typename = std::enable_if_t<std::is_convertible<S*,T*> >> ::value>> >> V8_INLINE Local(S* that) >> : val_(that) {} >> V8_INLINE static Local<T> New(Isolate* isolate, T* that); >> T* val_; >> >> >> This link http://ideone.com/RVL4rD shows overloaded functions being >> selected appropriately as well as pointer assignment working between >> compatible types. >> >> On Wednesday, January 27, 2016 at 5:03:49 PM UTC-8, xax...@gmail.com >> wrote: >>> >>> is_convertible doesn't seem to be the right test. I'm trying to figure >>> out if I can find a better one. >>> >>> On Wednesday, January 27, 2016 at 4:48:56 PM UTC-8, xax...@gmail.com >>> wrote: >>>> >>>> I have an overloaded function that can take either a std::string or a >>>> Local<Value>, however, when I pass in a const char *, expecting to have the >>>> std::string version selected, I instead get an ambiguity error. I added >>>> another version that takes a Local<Script> and that was added to the list >>>> of compatible overloaded functions for my call. >>>> >>>> The constructor at >>>> http://v8.paulfryzel.com/docs/master/include_2v8_8h_source.html line >>>> 332: >>>> >>>> template <class S> >>>> 333 V8_INLINE Local(S* that) >>>> 334 : val_(that) {} >>>> >>>> 336 T* val_; >>>> >>>> is what's causing me headaches. >>>> >>>> As far as I can tell, it doesn't matter if T* and S* are convertible, >>>> because when the compiler is looking for implicit conversions, it doesn't >>>> care if the compiler could actually succeed, just that the types match up. >>>> >>>> This means that any function that takes a Local<ANYTHING> will be a >>>> viable implicit conversion overload match for any pointer type. Is this a >>>> desirable behavior? >>>> >>>> >>>> I believe this code shows a way to use SFINAE to stop this from >>>> happening: http://ideone.com/cvZOHt >>>> >>>> basically: >>>> >>>> template <class S, typename = std::enable_if_t<std::is_convertible<T*,S >>>> *>::value>> >>>> V8_INLINE Local(S* that) >>>> : val_(that) {} >>>> V8_INLINE static Local<T> New(Isolate* isolate, T* that); >>>> T* val_; >>>> >>>> I believe std::is_convertible is the exact test as to whether : >>>> val_(that) will create a compilation error, but I don't know for sure. >>>> >>>> If this doesn't change any intended behavior, I'd love to see it merged >>>> in. >>>> Thank you. >>>> >>>> --Zac >>>> >>> -- > -- > v8-dev mailing list > v8-dev@googlegroups.com > http://groups.google.com/group/v8-dev > --- > You received this message because you are subscribed to the Google Groups > "v8-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to v8-dev+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- -- v8-dev mailing list v8-dev@googlegroups.com http://groups.google.com/group/v8-dev --- You received this message because you are subscribed to the Google Groups "v8-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-dev+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
