[Bug c++/115960] gcc throws an error when I use Optional in c++17.

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115960

--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #6)
> (In reply to Noah Williams from comment #5)
> > It isn't? The library I was trying to compile included the "optional"
> > header, and I had looked it up and found it was part of C++ 17, so I thought
> > it was part of the standard.
> 
> std::optional is part of C++17 but Optional is not.

And names in C++ are case sensitive. optional != Optional.