[Bug c++/85552] Adding curly braces to the declaration of a std::unique_ptr to a forward declared class breaks compilation

[tiagomacarios at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85552

--- Comment #4 from Tiago Macarios <tiagomacarios at gmail dot com> ---
Related clang bug: https://bugs.llvm.org/show_bug.cgi?id=39363