CMake searches for the optional header from https://github.com/akrzemi1/Optional
(mentioned in the NEWS file).
In future the checks needs to be extended to take also C++17 <optional> header into account (like configure does it already).
AFAIK the current used compilers don't support this header (or is the header already in gcc 6.x from Fedora 24?)
Hi Terry,
CMake searches for the optional header from https:/ /github. com/akrzemi1/ Optional
(mentioned in the NEWS file).
In future the checks needs to be extended to take also C++17 <optional> header into account (like configure does it already).
AFAIK the current used compilers don't support this header (or is the header already in gcc 6.x from Fedora 24?)