Comment by kibwen

Amusingly, C++ also supports Rust-style function headers, and has since C++11 (which is well before Rust was ever on the radar; really both C++ and Rust were inspired by ML here). The following two are identical in C++:

    u32 foo(u16 x, u16 y)
    auto foo(u16 x, u16 y) -> u32

IIRC there are contexts where the former does not work and the latter is required, which I believe means that ML-style function headers are strictly more powerful in C++ than the original C-style function headers.