Re: Issue 5368: Reduce allocations in Grob dimension caching (issue 359770043 by address@hidden)

[Hans Åberg]

> On 7 Jul 2018, at 00:13, address@hidden wrote:
> 
> On Jul 6, 2018, at 18:02, Hans Åberg <address@hidden> wrote:
> One can do it the other way around, too:
> #if __cplusplus < 201703L
> namespace std {
> using optional = Optional;
> }
> #endif
> 
> Ugh.  That’s too pragmatic [even] for me.

That came up on the Bison list in the context of the typed C++ parser, as a 
workaround for not having C++17 std::variant.

> I specifically avoided naming my class "optional" to avoid confusion
> with the standard type--but this is strictly academic now, as I’ve
> already moved it into Dimension_cache and reduced its interface.

The technique is useful for transforming code, though.