llvm-project/clang/test/SemaTemplate/qualified-names-diag.cpp

// RUN: clang-cc -fsyntax-only -verify %s

namespace std {
  template<typename T> class vector { };
}

typedef int INT;
typedef float Real;

void test() {
  using namespace std;

  std::vector<INT> v1;
  vector<Real> v2;
  v1 = v2; // expected-error{{incompatible type assigning 'vector<Real>' (aka 'class std::vector<float>'), expected 'std::vector<INT>' (aka 'class std::vector<int>')}}
}