Function detected_blake2b_backend 

pub fn detected_blake2b_backend() -> Blake2bBackend

The BLAKE2b Blake2bBackend this CPU resolved to, cached after the first call.

Diagnostic only — blake2b, blake2b_long, and every Argon2 hash call this for you. On aarch64 this is always Blake2bBackend::Scalar: a NEON compress was measured slower than the portable path, so there is no ARM SIMD backend to pick.

println!("argon2 blake2b backend: {}", argon2_rust::detected_blake2b_backend());