gcc/testsuite/g++.dg/lookup/crash3.C

// { dg-do compile }
// Contributed by Wolfgang Wieser <wwieser at gmx dot de>
// PR c++/15967: ICE with ambiguous operator new

typedef __SIZE_TYPE__ size_t; 

struct A { void *operator new(size_t s){ return 0; } };  // { dg-message "operator new" }
struct B { void *operator new(size_t s){ return 0; } };  // { dg-message "operator new" }

struct C : A,B {}; 

void crash() 
{
  C *c=new C();   // { dg-error "ambiguous" }
}