Function svset2_s8 

pub fn svset2_s8<const IMM_INDEX: i32>(
    tuple: svint8x2_t,
    x: svint8_t,
) -> svint8x2_t

🔬This is a nightly-only experimental API. (stdarch_aarch64_sve #145052)

Available on (AArch64 or ARM64EC) and target feature sve only.

Change one vector in a tuple of two vectors Arm’s documentation