With a bit of fiddeling you can use every kind of bracket to basically make function calls in c++
Here are the links to the snippets, all compile and run
Rust: https://godbolt.org/z/bM3d7bG14
You can overload the indexing operazor "[]" (std::vector does this for example), and since c++23 this operator can have more than one argument.
The last one is a constructor call with an overloaded conversion operator. The {} syntax is possible since c++11 I think. The conversion operator was already available before that