Commonly here on this mailing list, a person will post their new idea,
and very quickly a person will reply with "Oh check out paper P1234R5,
it does exactly what you're talking about".

I think we should have a dedicated website that has an AI that has
been given as input all of the C++ proposal papers, from P0001R0 up to
P3672R0.

So then we could ask it questions like:

    "Has anyone ever suggested that a class should be able to attain
multiple friends through the use of just one friend statement combined
with a parameter pack? For example: template<class... Ts> class
MyClass { friends... Ts; };"

or:

    "Has anyone ever suggested a new kind of R-value reference that is
always an R-value reference and never becomes an Lvalue?"

or:

    "Has anyone ever suggested that 'noexcept' could be a new
CV-qualifier applied to a variable? So that you can't invoke any of
its noexcept(true) methods?"

or:

    "Has anyone ever suggested that class inheritance could have a
'requires' clause? Something like: template<class... T> class MyClass
: public Ts... requires is_polymorphic_v<Ts> {};"

I've already created a website that has all C++ standard proposals
discussion topics going back to August of 1990, you can see it here:

   http://www.virjacode.com/cxxproposals/

 I think the next step is to have a dedicated website which has an AI that has:
    (1) processed all the papers from P0001R0 up to P3672R0
    (2) processed every proposal post from 1990 up to today

I think such a new website would be very useful when people come up
with a new idea.