// PR c++/91353 - P1331R2: Allow trivial default init in constexpr contexts. // { dg-do compile { target c++20 } } struct S { int i; }; constexpr void fn () { S s; []() constexpr { int i; }(); } constexpr int fn2 () { return __extension__ ({ int n; n; }); // { dg-error "not usable in a constant expression" } } constexpr int i = fn2 (); // { dg-message "in .constexpr. expansion of" }