[clang] template template argument has different template parameters

[bobby3605]

I'm trying to make a class that takes a container that takes a template as a template parameter for the class.
The following compiles in gcc, but not clang on 18.1.0. Clang trunk gives a different compilation error, which I am creating a separate issue for.
https://godbolt.org/z/j7cn3rd59
My guess is that it has something to do with the fact that std::vector takes two template arguments, one for the type, and one for the allocator. However, std::vector has a default argument for the allocator, so it only needs a single argument, but clang doesn't detect that.

[llvmbot]

@llvm/issue-subscribers-clang-frontend

Author: bobby3605 (bobby3605)

I'm trying to make a class that takes a container that takes a template as a template parameter for the class. The following compiles in gcc, but not clang on 18.1.0. Clang trunk gives a different compilation error, which I am creating a separate [issue](https://github.com//issues/95733) for. https://godbolt.org/z/j7cn3rd59 My guess is that it has something to do with the fact that std::vector takes two template arguments, one for the type, and one for the allocator. However, std::vector has a default argument for the allocator, so it only needs a single argument, but clang doesn't detect that.

[cor3ntin]

Fixed in trunk (Clang 19) or with -frelaxed-template-template-args https://godbolt.org/z/1Kah8zKGT