1 files changed, 31 insertions, 0 deletions
diff --git a/tests/lent/t16898.nim b/tests/lent/t16898.nim
new file mode 100644
index 000000000..a69c6d244
--- /dev/null
+++ b/tests/lent/t16898.nim
@@ -0,0 +1,31 @@
+discard """
+  errormsg: "invalid type: 'lent QuadraticExt' in this context: 'proc (r: var QuadraticExt, a: lent QuadraticExt, b: lent QuadraticExt){.noSideEffect, gcsafe.}' for proc"
+"""
+
+# bug #16898
+type
+  Fp[N: static int, T] = object
+    big: array[N, T]
+
+type
+  QuadraticExt* = concept x
+    ## Quadratic Extension concept (like complex)
+    type BaseField = auto
+    x.c0 is BaseField
+    x.c1 is BaseField
+
+{.experimental:"views".}
+
+func prod(r: var QuadraticExt, a, b: lent QuadraticExt) =
+  discard
+
+type
+  Fp2[N: static int, T] = object
+    c0, c1: Fp[N, T]
+
+# This should be passed by reference,
+# but concepts do not respect the 24 bytes rule
+# or `byref` pragma.
+var r, a, b: Fp2[6, uint64]
+
+prod(r, a, b)