Hi! This testcase got fixed with the PR98463 r11-6895-g94ff4c9dd98f39280fba22d1ad0958fb25a5363b fix.
Regtested on x86_64-linux, committed to trunk and 10 branch. 2021-02-03 Jakub Jelinek <ja...@redhat.com> PR c++/97804 * g++.dg/cpp2a/no_unique_address11.C: New test. --- gcc/testsuite/g++.dg/cpp2a/no_unique_address11.C.jj +++ gcc/testsuite/g++.dg/cpp2a/no_unique_address11.C @@ -0,0 +1,18 @@ +// PR c++/97804 +// { dg-do compile { target c++17 } } + +template <typename a> struct b { + constexpr b() : c() {} + [[no_unique_address]] a c; +}; +template <unsigned long, typename...> struct d; +template <unsigned long e, typename a, typename... f> +struct d<e, a, f...> : d<1, f...>, b<a> {}; +template <unsigned long e, typename a> struct d<e, a> : b<a> {}; +template <typename... g> class h : d<0, g...> {}; +struct i {}; +class j { + using k = int; + h<k, i> l; + float m = 0.025f; +} n; Jakub