I’m trying to upgrade my project’s clang-format version from 12 to 18. No changes were made in the project’s “.clang-format” file, I’ve only upgraded the version of the clang-format program. And clang-format 18 started to format structures inherited from decltype(...) differently.

Clang-format 12:

struct X : std::true_type
{
};

struct Y : decltype(std::true_type())
{
};

Clang-format 18:

struct X : std::true_type
{
};

struct Y : decltype(std::true_type()) {};

The AllowShortBlocksOnASingleLine parameter in my “.clang-format” has been set to Never, the BraceWrapping section is defined like this:

BraceWrapping:
  ...
  AfterClass: true
  AfterStruct: true
  AfterUnion: true
  IndentBraces: false
  SplitEmptyRecord: true

Is that a bug? Are there any workarounds to keep the old behavior with clang-format 18 and make such structs place their braces on separate lines, as clang-format 12 did?