llvm-project/clang/test/SemaTemplate/cxx17-inline-variables.cpp

// RUN: %clang_cc1 -std=c++17 -verify %s
// expected-no-diagnostics
template<bool> struct DominatorTreeBase {
  static constexpr bool IsPostDominator = true;
};
extern template class DominatorTreeBase<false>;
constexpr bool k = DominatorTreeBase<false>::IsPostDominator;

namespace CompleteType {
  template<unsigned N> constexpr int f(const bool (&)[N]) { return 0; }

  template<bool ...V> struct X {
    static constexpr bool arr[] = {V...};
    static constexpr int value = f(arr);
  };

  constexpr int n = X<true>::value;
}

template <typename T> struct A {
  static const int n;
  static const int m;
  constexpr int f() { return n; }
  constexpr int g() { return n; }
};
template <typename T> constexpr int A<T>::n = sizeof(A) + sizeof(T);
template <typename T> inline constexpr int A<T>::m = sizeof(A) + sizeof(T);
static_assert(A<int>().f() == 5);
static_assert(A<int>().g() == 5);