[PATCH 1/5] libstdc++: Import the fast_float library

[Jonathan Wakely]

On Tue, 16 Nov 2021 at 08:01, Florian Weimer wrote:
>
> * Patrick Palka via Libstdc:
>
> > This copies the fast_float library[1] into the compiled-in library
> > sources.  We're going to use this library in our floating-point
> > std::from_chars implementation for faster and more portable parsing of
> > binary32/64 decimal strings.
> >
> > [1]: https://github.com/fastfloat/fast_float
> >
> > Series tested on x86_64, i686, ppc64, ppc64le and aarch64, does it
> > look OK for trunk?
>
> Missing Signed-off-by:?

That's not needed if Patrick is still covered by an FSF assignment.

>
> > diff --git a/libstdc++-v3/src/c++17/fast_float/LICENSE-APACHE b/libstdc++-v3/src/c++17/fast_float/LICENSE-APACHE
> > new file mode 100644
> > index 00000000000..26f4398f249
> > --- /dev/null
> > +++ b/libstdc++-v3/src/c++17/fast_float/LICENSE-APACHE
> > @@ -0,0 +1,190 @@
> > +                                 Apache License
> > +                           Version 2.0, January 2004
> > +                        http://www.apache.org/licenses/
>
> > diff --git a/libstdc++-v3/src/c++17/fast_float/LICENSE-MIT b/libstdc++-v3/src/c++17/fast_float/LICENSE-MIT
> > new file mode 100644
> > index 00000000000..2fb2a37ad7f
> > --- /dev/null
> > +++ b/libstdc++-v3/src/c++17/fast_float/LICENSE-MIT
> > @@ -0,0 +1,27 @@
> > +MIT License
> > +
> > +Copyright (c) 2021 The fast_float authors
>
> You also need to include the README file, which makes it clear that
> recipients can choose between Apache and MIT.  GCC needs to use the MIT
> option, I think.

I think we could use Apache as well, because this code isn't going to
appear in public headers so the problematic clause doesn't apply. But
MIT is simpler.