From af3188bd16fe39eba0cf13ac343b912a9aaefed1 Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Tue, 25 Jan 2022 15:54:16 +1000
Subject: [PATCH] view: add read_array

---
 view.hpp | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/view.hpp b/view.hpp
index 6073a33a..6ce7de96 100644
--- a/view.hpp
+++ b/view.hpp
@@ -938,6 +938,30 @@ namespace cruft {
     }
 
 
+    /// Copy N elements of ValueT from a view over WordT into a supplied
+    /// std::array.
+    ///
+    /// Throws if there is insufficient data in the src view.
+    template <
+        typename ValueT,
+        typename WordT,
+        std::size_t N,
+        typename = std::enable_if_t<sizeof (ValueT) % sizeof(WordT) == 0>
+    >
+    std::array<ValueT, N>&
+    read_array (view<WordT*> &src, std::array<ValueT, N> &dst)
+    {
+        static_assert (std::is_trivially_copyable_v<ValueT>);
+
+        if (unlikely (src.size () * sizeof (WordT) < sizeof (dst)))
+            throw std::runtime_error ("insufficient data for extraction");
+
+        memcpy (dst.data (), src.data(), N * sizeof (ValueT));
+        src = src.consume (sizeof (ValueT) / sizeof (WordT) * N);
+        return dst;
+    }
+
+
     ///////////////////////////////////////////////////////////////////////////
     template <
         typename ValueT,