Replace hard coded references to the 32-byte key length with a constant, add utilities for copying data to and from fixed sized arrays

1 files changed, 49 insertions, 0 deletions

diff --git a/include/olm/memory.hh b/include/olm/memory.hh
index b19c74b..128990a 100644
--- a/include/olm/memory.hh
+++ b/include/olm/memory.hh
@@ -14,6 +14,8 @@
  */
 #include <cstddef>
 #include <cstdint>
+#include <cstring>
+#include <type_traits>
 
 namespace olm {
 
@@ -35,4 +37,51 @@ bool is_equal(
     std::size_t length
 );
 
+/** Check if two fixed size arrays are equals */
+template<typename T>
+bool array_equal(
+    T const & array_a,
+    T const & array_b
+) {
+    static_assert(
+        std::is_array<T>::value
+            && std::is_convertible<T, std::uint8_t *>::value
+            && sizeof(T) > 0,
+        "Arguments to array_equal must be std::uint8_t arrays[]."
+    );
+    return is_equal(array_a, array_b, sizeof(T));
+}
+
+/** Copy into a fixed size array */
+template<typename T>
+std::uint8_t const * load_array(
+    T & destination,
+    std::uint8_t const * source
+) {
+    static_assert(
+        std::is_array<T>::value
+            && std::is_convertible<T, std::uint8_t *>::value
+            && sizeof(T) > 0,
+        "The first argument to load_array must be a std::uint8_t array[]."
+    );
+    std::memcpy(destination, source, sizeof(T));
+    return source + sizeof(T);
+}
+
+/** Copy from a fixed size array */
+template<typename T>
+std::uint8_t * store_array(
+    std::uint8_t * destination,
+    T const & source
+) {
+    static_assert(
+        std::is_array<T>::value
+            && std::is_convertible<T, std::uint8_t *>::value
+            && sizeof(T) > 0,
+        "The second argument to store_array must be a std::uint8_t array[]."
+    );
+    std::memcpy(destination, source, sizeof(T));
+    return destination + sizeof(T);
+}
+
 } // namespace olm