Constant MAX_MEMORY 

pub const MAX_MEMORY: u32 = _; // 4_294_967_295u32

ARGON2_MAX_MEMORY = min(0xFFFFFFFF, 1 << ARGON2_MAX_MEMORY_BITS).

0xFFFF_FFFF on a 64-bit target, 0x0020_0000 on a 32-bit target. Verified against the C preprocessor on aarch64-apple-darwin.