🚀 go-pugleaf

There was some discussion going on whether the above construction
was legal.
Although it is not explicitly stated in ARM, it is a very important
construction, because:
Templates cannot be nested. Suppose you have a sort template that
should work as fast as possible on linked lists. It would look something
like:
template <class T, T * T::*link>
You could modify the link parameter to be a parameter for the
subroutine, but then you are replacing a compile time constant
by a variable which would usually assume one value anyhow.

Consider defining a Fourier transform working on arbitrary fields
with roots of 1.

Then you could use something like
template <class Field, unsigned N, Field * Nthroot>
and use it something like
Complex const NR = exp(2*pi*Complex(0,1)/N);
fft<Complex, 1024, &NR>.transform(...
or
Modular<64513> NR = 9; //Value is wrong
fft<Modular<64513>, 1024, &NR>.transform(...

Although it would work with complex numbers just as fast as usual,
it would without modification work even faster with other fields
as a base.

Other classes and functions might need other information
necessarily not included in the basic type, but being constant.

PLEASE let the template scopes begin immediately after their declaration,
not after the closing >.