added tg::shuffle

src/typed-geometry/feature/random.hh

@@ -3,4 +3,5 @@
 #include <typed-geometry/functions/random/gaussian.hh>
 #include <typed-geometry/functions/random/random.hh>
 #include <typed-geometry/functions/random/random_choice.hh>
+#include <typed-geometry/functions/random/shuffle.hh>
 #include <typed-geometry/functions/random/uniform.hh>

src/typed-geometry/functions/random/shuffle.hh

+#pragma once
+
+#include <typed-geometry/types/span.hh>
+
+namespace tg
+{
+template <class Rng, class T>
+constexpr void shuffle(Rng& rng, span<T> range)
+{
+    for (size_t i = 1; i < range.size(); ++i)
+    {
+        auto j = rng() % (i + 1);
+        if (i != j)
+            detail::swap(range[i], range[j]);
+    }
+}
+template <class Rng, class Range>
+constexpr void shuffle(Rng& rng, Range& range)
+{
+    shuffle(rng, tg::span(range));
+}
+}