Merge pull request #8506 from RazvanN7/Improve_error

Fix Issue 19098 - Improve error for non-assignable struct merged-on-behalf-of: Jacob Carlborg <jacob-carlborg@users.noreply.github.com>
dlang · Sep 6, 2018 · 7940798 · 7940798
2 parents 88de313 + 2d13435
commit 7940798
Show file tree

Hide file tree

Showing 2 changed files with 21 additions and 1 deletion.
diff --git a/src/dmd/expression.d b/src/dmd/expression.d
@@ -959,7 +959,8 @@ extern (C++) abstract class Expression : RootObject
             }
             else if (!type.isAssignable())
             {
-                error("cannot modify struct `%s` `%s` with `immutable` members", toChars(), type.toChars());
+                error("cannot modify struct instance `%s` of type `%s` because it contains `const` or `immutable` members",
+                    toChars(), type.toChars());
                 return new ErrorExp();
             }
         }

diff --git a/test/fail_compilation/fail19098.d b/test/fail_compilation/fail19098.d
@@ -0,0 +1,19 @@
+/*
+TEST_OUTPUT:
+---
+fail_compilation/fail19098.d(18): Error: cannot modify struct instance `a` of type `A` because it contains `const` or `immutable` members
+---
+*/
+
+struct A
+{
+    const int a;
+    this(int) {}
+}
+
+void main()
+{
+    A a = A(2);
+    A b = A(3);
+    a = b;
+}