chore: cleanup impl visibility and helpers

src/row/arch/neon.rs

@@ -119,7 +119,7 @@ pub(crate) unsafe fn yuv_420_to_rgba_row(
 /// bytes long.
 #[inline]
 #[target_feature(enable = "neon")]
-pub(crate) unsafe fn yuv_420_to_rgb_or_rgba_row<const ALPHA: bool>(
+unsafe fn yuv_420_to_rgb_or_rgba_row<const ALPHA: bool>(
   y: &[u8],
   u_half: &[u8],
   v_half: &[u8],
@@ -1214,10 +1214,7 @@ pub(crate) unsafe fn nv21_to_rgba_row(
 /// `vld2_u8`, `vst3q_u8` / `vst4q_u8`).
 #[inline]
 #[target_feature(enable = "neon")]
-pub(crate) unsafe fn nv12_or_nv21_to_rgb_or_rgba_row_impl<
-  const SWAP_UV: bool,
-  const ALPHA: bool,
->(
+unsafe fn nv12_or_nv21_to_rgb_or_rgba_row_impl<const SWAP_UV: bool, const ALPHA: bool>(
   y: &[u8],
   uv_or_vu_half: &[u8],
   out: &mut [u8],
@@ -1473,10 +1470,7 @@ pub(crate) unsafe fn nv42_to_rgba_row(
 /// No width parity constraint (4:4:4).
 #[inline]
 #[target_feature(enable = "neon")]
-pub(crate) unsafe fn nv24_or_nv42_to_rgb_or_rgba_row_impl<
-  const SWAP_UV: bool,
-  const ALPHA: bool,
->(
+unsafe fn nv24_or_nv42_to_rgb_or_rgba_row_impl<const SWAP_UV: bool, const ALPHA: bool>(
   y: &[u8],
   uv_or_vu: &[u8],
   out: &mut [u8],
@@ -1687,7 +1681,7 @@ pub(crate) unsafe fn yuv_444_to_rgba_row(
 /// No width parity constraint (4:4:4).
 #[inline]
 #[target_feature(enable = "neon")]
-pub(crate) unsafe fn yuv_444_to_rgb_or_rgba_row<const ALPHA: bool>(
+unsafe fn yuv_444_to_rgb_or_rgba_row<const ALPHA: bool>(
   y: &[u8],
   u: &[u8],
   v: &[u8],

src/row/arch/wasm_simd128.rs

@@ -122,7 +122,7 @@ pub(crate) unsafe fn yuv_420_to_rgba_row(
 /// bytes long.
 #[inline]
 #[target_feature(enable = "simd128")]
-pub(crate) unsafe fn yuv_420_to_rgb_or_rgba_row<const ALPHA: bool>(
+unsafe fn yuv_420_to_rgb_or_rgba_row<const ALPHA: bool>(
   y: &[u8],
   u_half: &[u8],
   v_half: &[u8],
@@ -1441,10 +1441,7 @@ pub(crate) unsafe fn nv21_to_rgba_row(
 /// 5. `out.len() >= width * (if ALPHA { 4 } else { 3 })`.
 #[inline]
 #[target_feature(enable = "simd128")]
-pub(crate) unsafe fn nv12_or_nv21_to_rgb_or_rgba_row_impl<
-  const SWAP_UV: bool,
-  const ALPHA: bool,
->(
+unsafe fn nv12_or_nv21_to_rgb_or_rgba_row_impl<const SWAP_UV: bool, const ALPHA: bool>(
   y: &[u8],
   uv_or_vu_half: &[u8],
   out: &mut [u8],
@@ -1702,10 +1699,7 @@ pub(crate) unsafe fn nv42_to_rgba_row(
 ///    `out.len() >= width * if ALPHA { 4 } else { 3 }`.
 #[inline]
 #[target_feature(enable = "simd128")]
-pub(crate) unsafe fn nv24_or_nv42_to_rgb_or_rgba_row_impl<
-  const SWAP_UV: bool,
-  const ALPHA: bool,
->(
+unsafe fn nv24_or_nv42_to_rgb_or_rgba_row_impl<const SWAP_UV: bool, const ALPHA: bool>(
   y: &[u8],
   uv_or_vu: &[u8],
   out: &mut [u8],
@@ -1969,7 +1963,7 @@ pub(crate) unsafe fn yuv_444_to_rgba_row(
 /// 3. `out.len() >= width * (if ALPHA { 4 } else { 3 })`.
 #[inline]
 #[target_feature(enable = "simd128")]
-pub(crate) unsafe fn yuv_444_to_rgb_or_rgba_row<const ALPHA: bool>(
+unsafe fn yuv_444_to_rgb_or_rgba_row<const ALPHA: bool>(
   y: &[u8],
   u: &[u8],
   v: &[u8],

src/row/arch/x86_avx2.rs

@@ -132,7 +132,7 @@ pub(crate) unsafe fn yuv_420_to_rgba_row(
 /// bytes long.
 #[inline]
 #[target_feature(enable = "avx2")]
-pub(crate) unsafe fn yuv_420_to_rgb_or_rgba_row<const ALPHA: bool>(
+unsafe fn yuv_420_to_rgb_or_rgba_row<const ALPHA: bool>(
   y: &[u8],
   u_half: &[u8],
   v_half: &[u8],
@@ -1646,10 +1646,7 @@ pub(crate) unsafe fn nv21_to_rgba_row(
 /// 5. `out.len() >= width * (if ALPHA { 4 } else { 3 })`.
 #[inline]
 #[target_feature(enable = "avx2")]
-pub(crate) unsafe fn nv12_or_nv21_to_rgb_or_rgba_row_impl<
-  const SWAP_UV: bool,
-  const ALPHA: bool,
->(
+unsafe fn nv12_or_nv21_to_rgb_or_rgba_row_impl<const SWAP_UV: bool, const ALPHA: bool>(
   y: &[u8],
   uv_or_vu_half: &[u8],
   out: &mut [u8],
@@ -1898,10 +1895,7 @@ pub(crate) unsafe fn nv42_to_rgba_row(
 /// 4. `out.len() >= width * if ALPHA { 4 } else { 3 }`.
 #[inline]
 #[target_feature(enable = "avx2")]
-pub(crate) unsafe fn nv24_or_nv42_to_rgb_or_rgba_row_impl<
-  const SWAP_UV: bool,
-  const ALPHA: bool,
->(
+unsafe fn nv24_or_nv42_to_rgb_or_rgba_row_impl<const SWAP_UV: bool, const ALPHA: bool>(
   y: &[u8],
   uv_or_vu: &[u8],
   out: &mut [u8],
@@ -2144,7 +2138,7 @@ pub(crate) unsafe fn yuv_444_to_rgba_row(
 /// 3. `out.len() >= width * (if ALPHA { 4 } else { 3 })`.
 #[inline]
 #[target_feature(enable = "avx2")]
-pub(crate) unsafe fn yuv_444_to_rgb_or_rgba_row<const ALPHA: bool>(
+unsafe fn yuv_444_to_rgb_or_rgba_row<const ALPHA: bool>(
   y: &[u8],
   u: &[u8],
   v: &[u8],

src/row/arch/x86_avx512.rs

@@ -146,7 +146,7 @@ pub(crate) unsafe fn yuv_420_to_rgba_row(
 /// bytes long.
 #[inline]
 #[target_feature(enable = "avx512f,avx512bw")]
-pub(crate) unsafe fn yuv_420_to_rgb_or_rgba_row<const ALPHA: bool>(
+unsafe fn yuv_420_to_rgb_or_rgba_row<const ALPHA: bool>(
   y: &[u8],
   u_half: &[u8],
   v_half: &[u8],
@@ -1693,10 +1693,7 @@ pub(crate) unsafe fn nv21_to_rgba_row(
 /// 5. `out.len() >= width * (if ALPHA { 4 } else { 3 })`.
 #[inline]
 #[target_feature(enable = "avx512f,avx512bw")]
-pub(crate) unsafe fn nv12_or_nv21_to_rgb_or_rgba_row_impl<
-  const SWAP_UV: bool,
-  const ALPHA: bool,
->(
+unsafe fn nv12_or_nv21_to_rgb_or_rgba_row_impl<const SWAP_UV: bool, const ALPHA: bool>(
   y: &[u8],
   uv_or_vu_half: &[u8],
   out: &mut [u8],
@@ -1950,10 +1947,7 @@ pub(crate) unsafe fn nv42_to_rgba_row(
 /// 4. `out.len() >= width * if ALPHA { 4 } else { 3 }`.
 #[inline]
 #[target_feature(enable = "avx512f,avx512bw")]
-pub(crate) unsafe fn nv24_or_nv42_to_rgb_or_rgba_row_impl<
-  const SWAP_UV: bool,
-  const ALPHA: bool,
->(
+unsafe fn nv24_or_nv42_to_rgb_or_rgba_row_impl<const SWAP_UV: bool, const ALPHA: bool>(
   y: &[u8],
   uv_or_vu: &[u8],
   out: &mut [u8],
@@ -2209,7 +2203,7 @@ pub(crate) unsafe fn yuv_444_to_rgba_row(
 /// 3. `out.len() >= width * (if ALPHA { 4 } else { 3 })`.
 #[inline]
 #[target_feature(enable = "avx512f,avx512bw")]
-pub(crate) unsafe fn yuv_444_to_rgb_or_rgba_row<const ALPHA: bool>(
+unsafe fn yuv_444_to_rgb_or_rgba_row<const ALPHA: bool>(
   y: &[u8],
   u: &[u8],
   v: &[u8],

src/row/arch/x86_sse41.rs

@@ -132,7 +132,7 @@ pub(crate) unsafe fn yuv_420_to_rgba_row(
 /// bytes long.
 #[inline]
 #[target_feature(enable = "sse4.1")]
-pub(crate) unsafe fn yuv_420_to_rgb_or_rgba_row<const ALPHA: bool>(
+unsafe fn yuv_420_to_rgb_or_rgba_row<const ALPHA: bool>(
   y: &[u8],
   u_half: &[u8],
   v_half: &[u8],
@@ -1460,10 +1460,7 @@ pub(crate) unsafe fn nv21_to_rgba_row(
 /// 5. `out.len() >= width * (if ALPHA { 4 } else { 3 })`.
 #[inline]
 #[target_feature(enable = "sse4.1")]
-pub(crate) unsafe fn nv12_or_nv21_to_rgb_or_rgba_row_impl<
-  const SWAP_UV: bool,
-  const ALPHA: bool,
->(
+unsafe fn nv12_or_nv21_to_rgb_or_rgba_row_impl<const SWAP_UV: bool, const ALPHA: bool>(
   y: &[u8],
   uv_or_vu_half: &[u8],
   out: &mut [u8],
@@ -1693,10 +1690,7 @@ pub(crate) unsafe fn nv42_to_rgba_row(
 /// 4. `out.len() >= width * if ALPHA { 4 } else { 3 }`.
 #[inline]
 #[target_feature(enable = "sse4.1")]
-pub(crate) unsafe fn nv24_or_nv42_to_rgb_or_rgba_row_impl<
-  const SWAP_UV: bool,
-  const ALPHA: bool,
->(
+unsafe fn nv24_or_nv42_to_rgb_or_rgba_row_impl<const SWAP_UV: bool, const ALPHA: bool>(
   y: &[u8],
   uv_or_vu: &[u8],
   out: &mut [u8],
@@ -1909,7 +1903,7 @@ pub(crate) unsafe fn yuv_444_to_rgba_row(
 /// 3. `out.len() >= width * (if ALPHA { 4 } else { 3 })`.
 #[inline]
 #[target_feature(enable = "sse4.1")]
-pub(crate) unsafe fn yuv_444_to_rgb_or_rgba_row<const ALPHA: bool>(
+unsafe fn yuv_444_to_rgb_or_rgba_row<const ALPHA: bool>(
   y: &[u8],
   u: &[u8],
   v: &[u8],

src/row/mod.rs

@@ -34,6 +34,12 @@
 pub(crate) mod arch;
 pub(crate) mod scalar;
 
+// Re-exported only when a caller is compiled. The `MixedSinker` Strategy A
+// fan-out is the sole consumer, and it lives in `crate::sinker::mixed` which
+// is gated on `feature = "std"` / `feature = "alloc"` (needs `Vec`). Without
+// either feature both this re-export and the underlying scalar function would
+// be unused, which is a hard error under `cargo clippy -- -D warnings`.
+#[cfg(any(feature = "std", feature = "alloc"))]
 pub(crate) use scalar::expand_rgb_to_rgba_row;
 
 use crate::ColorMatrix;

src/row/scalar.rs

@@ -220,7 +220,7 @@ pub(crate) fn nv21_to_rgba_row(
 /// - `y.len() >= width`, `uv_or_vu_half.len() >= width`,
 ///   `out.len() >= width * (if ALPHA { 4 } else { 3 })`.
 #[cfg_attr(not(tarpaulin), inline(always))]
-pub(crate) fn nv12_or_nv21_to_rgb_or_rgba_row_impl<const SWAP_UV: bool, const ALPHA: bool>(
+fn nv12_or_nv21_to_rgb_or_rgba_row_impl<const SWAP_UV: bool, const ALPHA: bool>(
   y: &[u8],
   uv_or_vu_half: &[u8],
   out: &mut [u8],
@@ -353,7 +353,7 @@ pub(crate) fn nv42_to_rgba_row(
 /// - `y.len() >= width`, `uv_or_vu.len() >= 2 * width`,
 ///   `out.len() >= width * (if ALPHA { 4 } else { 3 })`.
 #[cfg_attr(not(tarpaulin), inline(always))]
-pub(crate) fn nv24_or_nv42_to_rgb_or_rgba_row_impl<const SWAP_UV: bool, const ALPHA: bool>(
+fn nv24_or_nv42_to_rgb_or_rgba_row_impl<const SWAP_UV: bool, const ALPHA: bool>(
   y: &[u8],
   uv_or_vu: &[u8],
   out: &mut [u8],
@@ -445,7 +445,7 @@ pub(crate) fn yuv_444_to_rgba_row(
 /// - `y.len() >= width`, `u.len() >= width`, `v.len() >= width`,
 ///   `out.len() >= width * (if ALPHA { 4 } else { 3 })`.
 #[cfg_attr(not(tarpaulin), inline(always))]
-pub(crate) fn yuv_444_to_rgb_or_rgba_row<const ALPHA: bool>(
+fn yuv_444_to_rgb_or_rgba_row<const ALPHA: bool>(
   y: &[u8],
   u: &[u8],
   v: &[u8],
@@ -509,6 +509,11 @@ fn clamp_u8(v: i32) -> u8 {
 ///
 /// - `rgb.len() >= 3 * width`
 /// - `rgba_out.len() >= 4 * width`
+// Only the `MixedSinker` Strategy A fan-out calls this; that lives in
+// `crate::sinker::mixed`, gated on `feature = "std"` / `"alloc"`. Without
+// either feature the helper would be unused and `-D dead_code` (set by
+// `cargo clippy -- -D warnings` on CI) would fail the build.
+#[cfg(any(feature = "std", feature = "alloc"))]
 #[cfg_attr(not(tarpaulin), inline(always))]
 pub(crate) fn expand_rgb_to_rgba_row(rgb: &[u8], rgba_out: &mut [u8], width: usize) {
   debug_assert!(rgb.len() >= width * 3, "rgb row too short");

src/sinker/mixed/bayer.rs

@@ -1,12 +1,10 @@
 //! Bayer / Bayer16 RAW `MixedSinker` impls.
 
-#![allow(unused_imports)]
-
 use super::{
-  HsvBuffers, HsvPlane, LumaChannel, LumaCoefficients, MixedSinker, MixedSinkerError, RowSlice,
-  check_dimensions_match, rgb_row_to_luma_row,
+  LumaCoefficients, MixedSinker, MixedSinkerError, RowSlice, check_dimensions_match,
+  rgb_row_buf_or_scratch, rgb_row_to_luma_row,
 };
-use crate::{ColorMatrix, PixelSink, SourceFormat, raw::*, row::*, yuv::*};
+use crate::{PixelSink, raw::*, row::*};
 
 // ---- Bayer (8-bit) impl --------------------------------------------------
 
@@ -116,31 +114,14 @@ impl PixelSink for MixedSinker<'_, Bayer> {
     // 8-bit RGB scratch / output buffer. Bayer always derives every
     // output channel from the demosaiced RGB, so the RGB row exists
     // unconditionally when any of `rgb` / `luma` / `hsv` is set.
-    let rgb_row: &mut [u8] = match rgb.as_deref_mut() {
-      Some(buf) => {
-        let rgb_plane_end =
-          one_plane_end
-            .checked_mul(3)
-            .ok_or(MixedSinkerError::GeometryOverflow {
-              width: w,
-              height: h,
-              channels: 3,
-            })?;
-        let rgb_plane_start = one_plane_start * 3;
-        &mut buf[rgb_plane_start..rgb_plane_end]
-      }
-      None => {
-        let rgb_row_bytes = w.checked_mul(3).ok_or(MixedSinkerError::GeometryOverflow {
-          width: w,
-          height: h,
-          channels: 3,
-        })?;
-        if rgb_scratch.len() < rgb_row_bytes {
-          rgb_scratch.resize(rgb_row_bytes, 0);
-        }
-        &mut rgb_scratch[..rgb_row_bytes]
-      }
-    };
+    let rgb_row = rgb_row_buf_or_scratch(
+      rgb.as_deref_mut(),
+      rgb_scratch,
+      one_plane_start,
+      one_plane_end,
+      w,
+      h,
+    )?;
 
     bayer_to_rgb_row(
       row.above(),
@@ -336,31 +317,14 @@ impl<const BITS: u32> PixelSink for MixedSinker<'_, Bayer16<BITS>> {
 
     // 8-bit RGB scratch / output. Same lazy-grow pattern as the
     // 8-bit Bayer impl above.
-    let rgb_row: &mut [u8] = match rgb.as_deref_mut() {
-      Some(buf) => {
-        let rgb_plane_end =
-          one_plane_end
-            .checked_mul(3)
-            .ok_or(MixedSinkerError::GeometryOverflow {
-              width: w,
-              height: h,
-              channels: 3,
-            })?;
-        let rgb_plane_start = one_plane_start * 3;
-        &mut buf[rgb_plane_start..rgb_plane_end]
-      }
-      None => {
-        let rgb_row_bytes = w.checked_mul(3).ok_or(MixedSinkerError::GeometryOverflow {
-          width: w,
-          height: h,
-          channels: 3,
-        })?;
-        if rgb_scratch.len() < rgb_row_bytes {
-          rgb_scratch.resize(rgb_row_bytes, 0);
-        }
-        &mut rgb_scratch[..rgb_row_bytes]
-      }
-    };
+    let rgb_row = rgb_row_buf_or_scratch(
+      rgb.as_deref_mut(),
+      rgb_scratch,
+      one_plane_start,
+      one_plane_end,
+      w,
+      h,
+    )?;
 
     bayer16_to_rgb_row::<BITS>(
       row.above(),