gcc/testsuite/gdc.test/fail_compilation/must_use_opunary.d

   1 /+
   2 TEST_OUTPUT:
   3 ---
   4 fail_compilation/must_use_opunary.d(20): Error: ignored value of `@mustuse` type `must_use_opunary.S`; prepend a `cast(void)` if intentional
   5 ---
   6 +/
   7 import core.attribute;
   8
   9 @mustuse struct S
  10 {
  11     ref S opUnary(string op)() return
  12     {
  13         return this;
  14     }
  15 }
  16
  17 void test()
  18 {
  19     S s;
  20     -s;
  21 }