test/SemaCXX/inc-decrement-qualifiers.cpp

// RUN: %clang_cc1 -fsyntax-only -verify %s

volatile int i;

const int &inc = i++;
const int &dec = i--;

const int &incfail = ++i; // expected-error {{drops qualifiers}}
const int &decfail = --i; // expected-error {{drops qualifiers}}