LibCore: Add support for non-trivial types to `Stream::*_value`

At the moment, there is no immediate advantage compared to just calling
the underlying functions directly, but having a common interface feels
more ergonomic (users don't have to care about how a type serializes)
and maybe we'll find a way to hide the actual implementation from direct
access some time in the future.

1 files changed, 14 insertions, 0 deletions

diff --git a/Userland/Libraries/LibCore/Stream.h b/Userland/Libraries/LibCore/Stream.h
index 7e3cf6f23a..1351a41a8a 100644
--- a/Userland/Libraries/LibCore/Stream.h
+++ b/Userland/Libraries/LibCore/Stream.h
@@ -102,6 +102,13 @@ public:
     virtual ErrorOr<void> write_entire_buffer(ReadonlyBytes);
 
     template<typename T>
+    requires(requires(Stream& stream) { { T::read_from_stream(stream) } -> SameAs<ErrorOr<T>>; })
+    ErrorOr<T> read_value()
+    {
+        return T::read_from_stream(*this);
+    }
+
+    template<typename T>
     requires(Traits<T>::is_trivially_serializable())
     ErrorOr<T> read_value()
     {
@@ -111,6 +118,13 @@ public:
     }
 
     template<typename T>
+    requires(requires(T t, Stream& stream) { { t.write_to_stream(stream) } -> SameAs<ErrorOr<void>>; })
+    ErrorOr<void> write_value(T const& value)
+    {
+        return value.write_to_stream(*this);
+    }
+
+    template<typename T>
     requires(Traits<T>::is_trivially_serializable())
     ErrorOr<void> write_value(T const& value)
     {