Function tuple_view 

pub fn tuple_view(children: &[View]) -> View

TupleView<(A, B, …)> — several views with no container around them.

This is what a @ViewBuilder block evaluates to, and it is why List { Text("a"); Text("b") } is two rows: a List renders each element of its content. Wrapping them in a stack instead gives one row holding a stack, which is a different screen.

Usually reached through the container macros — crate::list!, crate::form!, crate::section! — rather than called directly.