--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/g++.dg/cpp0x/overload-conv-4.C	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,23 @@
+// PR c++/90998 - ICE with copy elision in init by ctor and -Wconversion.
+// { dg-do compile { target c++11 } }
+// { dg-options "-Wconversion" }
+
+struct B;
+
+struct A {
+    operator B();
+};
+
+struct B {
+    B(A const &rs);
+    B(B const &rs);
+};
+
+B
+f (A x)
+{
+  // C++14: we call B::B(A const &)
+  // C++17: we call A::operator B()
+  return B(x); // { dg-warning "choosing .A::operator B\\(\\). over .B::B\\(const A&\\)" "" { target c++17 } }
+  // { dg-warning "for conversion from .A. to .B." "" { target c++17 } .-1 }
+}