Otherwise a custom <code>Read</code> can be constructed using the <code>Uint64</code> method.

<li>The global generator accessed by top-level functions is unconditionally randomly seeded.
Because the API guarantees no fixed sequence of results,
optimizations like per-thread random generator states are now possible.

<li>The <a href="/pkg/math/rand/v2/#Source"><code>Source</code></a>
interface now has a single <code>Uint64</code> method;

The set of permissible values is determined by the
variable's <i><a href="#Types">type</a></i>.
</p>

<p>
A <a href="#Variable_declarations">variable declaration</a>
or, for function parameters and results, the signature
of a <a href="#Function_declarations">function declaration</a>
or <a href="#Function_literals">function literal</a> reserves
storage for a named variable.

The set of permissible values is determined by the
variable's <i><a href="#Types">type</a></i>.
</p>

<p>
A <a href="#Variable_declarations">variable declaration</a>
or, for function parameters and results, the signature
of a <a href="#Function_declarations">function declaration</a>
or <a href="#Function_literals">function literal</a> reserves
storage for a named variable.

At the start of the function, the arguments are assumed
to be initialized but the results are assumed uninitialized.
If the results will hold live pointers during a call instruction,
the function should start by zeroing the results and then
executing the pseudo-instruction <code>GO_RESULTS_INITIALIZED</code>.
This instruction records that the results are now initialized
and should be scanned during stack movement and garbage collection.