unwrap_or_else VS match Ok and Err

内核开发
1

From alloc::raw_vec::RawVecInner::try_allocate_in we have:

// We avoid `unwrap_or_else` here because it bloats the amount of
// LLVM IR generated.
let layout = match layout_array(capacity, elem_layout) {
    Ok(layout) => layout,
    Err(_) => return Err(CapacityOverflow.into()),
};

It said that avoid using unwrap_or_else because it bloats the amount of LLVM IR generated.