gcc/testsuite/gdc.test/fail_compilation/fail6107.d

/*
TEST_OUTPUT:
---
fail_compilation/fail6107.d(10): Error: variable fail6107.Foo.__ctor is not a constructor; identifiers starting with __ are reserved for the implementation
fail_compilation/fail6107.d(14): Error: variable fail6107.Bar.__ctor is not a constructor; identifiers starting with __ are reserved for the implementation
---
*/
struct Foo
{
    enum __ctor = 4;
}
class Bar
{
    int __ctor = 4;
}