Translate concepts and requires expressions

[lucic71]

They are evaluated by clang. Only the result of the evaluation is translated.

Furthermore, static_assert is no-op because it's evaluated at compile time. Same for concept declaration.

[nunoplopes]

It would be nice to translate these statements rather than constant fold at compile time.

[lucic71]

It would be nice to translate these statements rather than constant fold at compile time.

I think i can keep static_asserts, concepts and requires would be too difficult to keep now.

[lucic71]

It would be nice to translate these statements rather than constant fold at compile time.

Done, I translate static_assert as const assert in Rust.

For the things that can be const evaluated in rust I keep the expression inside static_assert, e.g. const _: () = assert!(size_of(int) == 4).

For the things that cannot be const-evaluated (non-const Rust functions) or for the things that don't have a direct translation to Rust (concepts and requires) I write: const _: () = assert!(true, "Small<int>") to keep track of the C++ expression that generated the code.