3 files changed, 62 insertions, 1 deletions
diff --git a/tests/compute/enum-tag-conversion.slang b/tests/compute/enum-tag-conversion.slang
index 66b4923e5..5758cc3c1 100644
--- a/tests/compute/enum-tag-conversion.slang
+++ b/tests/compute/enum-tag-conversion.slang
@@ -13,7 +13,7 @@ enum RoseColors
 
 int test(int val)
 {
-	return val + RoseColors.Red;
+	return val + int(RoseColors.Red);
 }
 
 //TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):dxbinding(0),glbinding(0),out
diff --git a/tests/diagnostics/enum-implicit-conversion.slang b/tests/diagnostics/enum-implicit-conversion.slang
new file mode 100644
index 000000000..d3f3d1d28
--- /dev/null
+++ b/tests/diagnostics/enum-implicit-conversion.slang
@@ -0,0 +1,48 @@
+// enum-implicit-conversion.slang
+
+//TEST:SIMPLE:
+
+// Confirm that suitable error messages are
+// generated for code that relies on implicit
+// conversion of integers to/from `enum` types.
+
+enum Color
+{
+    Red,
+    Green,
+    Blue,
+    Alpha,
+}
+
+int foo(int  x) { return x * 16; }
+int foo(uint x) { return x * 256 * 16; }
+
+int bar(Color x) { return int(x) * 256; }
+int bar(int   x) { return x * 256 * 256; }
+int bar(uint  x) { return x * 256 * 256 * 16; }
+
+int test(int val)
+{
+    // Implicit conversion from `int` to `enum` isn't allowed.
+    Color c = val;
+
+    // TODO: explicit conversion to `enum` type should be allowed.
+//	Color cc = Color(val);
+
+
+    // Implicit converion from `enum` to `int` isn't allowed.
+	int  x = c;
+    uint y = c;
+
+    // Explicit converion is allowed.
+    int  xx = int(c);
+    uint yy = uint(c);
+
+    // Call that expects implicit conversion should fail.
+    int z = foo(c);
+
+    // Call that has an explicit overload on `enum` type should succeed.
+    int zz = bar(c);
+
+    return x + y + z;
+}
diff --git a/tests/diagnostics/enum-implicit-conversion.slang.expected b/tests/diagnostics/enum-implicit-conversion.slang.expected
new file mode 100644
index 000000000..7564e0aa4
--- /dev/null
+++ b/tests/diagnostics/enum-implicit-conversion.slang.expected
@@ -0,0 +1,13 @@
+result code = -1
+standard error = {
+tests/diagnostics/enum-implicit-conversion.slang(27): error 30019: expected an expression of type 'Color', got 'int'
+tests/diagnostics/enum-implicit-conversion.slang(34): error 30019: expected an expression of type 'int', got 'Color'
+tests/diagnostics/enum-implicit-conversion.slang(34): note: explicit conversion from 'Color' to 'int' is possible
+tests/diagnostics/enum-implicit-conversion.slang(35): error 30019: expected an expression of type 'uint', got 'Color'
+tests/diagnostics/enum-implicit-conversion.slang(35): note: explicit conversion from 'Color' to 'uint' is possible
+tests/diagnostics/enum-implicit-conversion.slang(42): error 39999: ambiguous call to overloaded operation with arguments of type (Color)
+tests/diagnostics/enum-implicit-conversion.slang(18): note 39999: candidate: foo(uint)
+tests/diagnostics/enum-implicit-conversion.slang(17): note 39999: candidate: foo(int)
+}
+standard output = {
+}