Function vduph_lane_f16 

pub fn vduph_lane_f16(a: float16x4_t, const N: i32) -> f16

🔬This is a nightly-only experimental API. (stdarch_neon_f16 #136306)

Available on (AArch64 or target_arch="arm64ec") and target feature neon and target feature fp16 only.

Set all vector lanes to the same value Arm’s documentation