Hi again Jonny,

your proposed solution is actually not posible to implement without
special "compiler magic" if I understood you correctly. However it would
be also a very narrow soltion to a bigger problem (reflection).

Reflection is a topic which is investigated by WG21 since a few years
(in its own study group - SG7). There is currently a separate TS for
reflection in the makings which would solve your problem at a wider
scope (reflection to obtain types/names, etc. on all kinds of
identifiers).

https://en.cppreference.com/w/cpp/experimental
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/n4818.pdf
https://github.com/cplusplus/reflection-ts

These documents are not up to date with the latest decisions made by SG7
in Cologne after this week (however you can expect similar features).
I suggest you to have a look at the current reflection documents (see
pre mailing of the Cologne meeting and the post meeting once it becomes
available on isocpp.org).

Cheers,
Sebastian

On 2019-07-20 22:34, Jonny Grant wrote:

> Hi Sebastian
>
> Many thanks for your reply. yes, better I avoid using this typeid(), it
> only gives the type.. not the enum class name "Red" I had hoped for etc
>
> Yes, I would prefer to avoid using typeid().
>
> My proposal would be if there could be just a .name() on all 'enum
> class' ?
>
> Thanks
> Jonny
>
> On 20/07/2019 21:27, Sebastian Büttner wrote: Hi Jonny,
>
> you might want to wait for reflection to do such things.
>
> Relying on the name returned by a std::type_info object is not a save
> way anyway since the returned name is implementation defined.
>
> See: http://eel.is/c++draft/type.info#9 - This is also why you get
> something "strange" like 5Color for your color enum on some
> implementations.
>
> Cheers,
> Sebastian
>
> On 2019-07-20 22:16, Jonny Grant via Std-Proposals wrote:
> Hello
>
> Could I ask if enum class has been considered to add a way to get a
> string representation from an enum? ie "Red" and "Blue" below.
> typeid() just returns the enum class name.
>
> Very useful for logs/debugging.
>
> Read the initial link about enum class:
> http://www.stroustrup.com/C++11FAQ.html#enum
>
> ie, what I am asking is if for example:
> // g++-8 -Wall -o typeid typeid.cpp
>
> #include <iostream>
> #include <string>
> #include <typeinfo>
>
> enum class Color { Red, Blue };
>
> int main()
> {
> Color c = Color::Red;
>
> std::cout << "my enum is " << typeid(c).name() << std::endl;
>
> std::cout << "my enum is " << c.name() << std::endl;
>
> std::cout << "my enum is " << Color::Blue.name() << std::endl;
> }
>
> (if it compiled) the output would be:
>
> my enum is Color
> my enum is Red
> my enum is Blue
>
> But the later two lines do not compile
>
> The first does work, but only gives the type.
>
> $ ./typeid
> my enum is 5Color
>
> Strange that this one is '5Color'
>
> Could it be done by the typeid() on enum class?
>
> This saves me needing to write for every enum
>
> const char * get_enum_str(Color value);
>
> There are a lot of posts online discussing similar
>
> https://stackoverflow.com/questions/28828957/enum-to-string-in-modern-c11-c14-c17-and-future-c20
>
> Has there been a proposal someone could point me to please?
>
> Jonny
> .