add branch hints

Author: fereidani

Cargo.toml

@@ -22,6 +22,7 @@ members = [
 [dependencies]
 soa_derive_internal = {path = "soa-derive-internal", version = "0.14"}
 permutation = "0.4.0"
+branches = { version = "0.4.0", default-features = false }
 
 [dev-dependencies]
 bencher = "0.1"

soa-derive-internal/src/ptr.rs

@@ -108,7 +108,7 @@ pub fn derive(input: &Input) -> TokenStream {
             /// Similar to [`*const T::as_ref()`](https://doc.rust-lang.org/std/primitive.pointer.html#method.as_ref),
             /// with the same safety caveats.
             pub unsafe fn as_ref<'a>(self) -> Option<#ref_name<'a>> {
-                if self.is_null() {
+                if ::branches::unlikely(self.is_null()) {
                     None
                 } else {
                     Some(#ref_name {
@@ -214,7 +214,7 @@ pub fn derive(input: &Input) -> TokenStream {
             /// Similar to [`*mut T::as_ref()`](https://doc.rust-lang.org/std/primitive.pointer.html#method.as_ref),
             /// with the same safety caveats.
             pub unsafe fn as_ref<'a>(self) -> Option<#ref_name<'a>> {
-                if self.is_null() {
+                if ::branches::unlikely(self.is_null()) {
                     None
                 } else {
                     Some(#ref_name {
@@ -226,7 +226,7 @@ pub fn derive(input: &Input) -> TokenStream {
             /// Similar to [`*mut T::as_mut()`](https://doc.rust-lang.org/std/primitive.pointer.html#method.as_mut),
             /// with the same safety caveats.
             pub unsafe fn as_mut<'a>(self) -> Option<#ref_mut_name<'a>> {
-                if self.is_null() {
+                if ::branches::unlikely(self.is_null()) {
                     None
                 } else {
                     Some(#ref_mut_name {

soa-derive-internal/src/slice.rs

@@ -101,7 +101,7 @@ pub fn derive(input: &Input) -> TokenStream {
             #[doc = #slice_name_str]
             /// ::first()`](https://doc.rust-lang.org/std/primitive.slice.html#method.first).
             pub fn first(&self) -> Option<#ref_name<'a>> {
-                if self.is_empty() {
+                if ::branches::unlikely(self.is_empty()) {
                     None
                 } else {
                     #(
@@ -115,7 +115,7 @@ pub fn derive(input: &Input) -> TokenStream {
             #[doc = #slice_name_str]
             /// ::split_first()`](https://doc.rust-lang.org/std/primitive.slice.html#method.split_first).
             pub fn split_first(&self) -> Option<(#ref_name<'a>, #slice_name<'a>)> {
-                if self.is_empty() {
+                if ::branches::unlikely(self.is_empty()) {
                     None
                 } else {
                     #(
@@ -131,7 +131,7 @@ pub fn derive(input: &Input) -> TokenStream {
             #[doc = #slice_name_str]
             /// ::last()`](https://doc.rust-lang.org/std/primitive.slice.html#method.last).
             pub fn last(&self) -> Option<#ref_name<'a>> {
-                if self.is_empty() {
+                if ::branches::unlikely(self.is_empty()) {
                     None
                 } else {
                     #(
@@ -145,7 +145,7 @@ pub fn derive(input: &Input) -> TokenStream {
             #[doc = #slice_name_str]
             /// ::split_last()`](https://doc.rust-lang.org/std/primitive.slice.html#method.split_last).
             pub fn split_last(&self) -> Option<(#ref_name<'a>, #slice_name<'a>)> {
-                if self.is_empty() {
+                if ::branches::unlikely(self.is_empty()) {
                     None
                 } else {
                     #(
@@ -402,7 +402,7 @@ pub fn derive_mut(input: &Input) -> TokenStream {
             #[doc = #slice_name_str]
             /// ::first_mut()`](https://doc.rust-lang.org/std/primitive.slice.html#method.first_mut).
             pub fn first_mut(&mut self) -> Option<#ref_mut_name> {
-                if self.is_empty() {
+                if ::branches::unlikely(self.is_empty()) {
                     None
                 } else {
                     #(
@@ -420,7 +420,7 @@ pub fn derive_mut(input: &Input) -> TokenStream {
             /// You should use [`Self::reborrow()`] first if you want the
             /// returned values to have a shorter lifetime.
             pub fn split_first_mut(mut self) -> Option<(#ref_mut_name<'a>, #slice_mut_name<'a>)> {
-                if self.is_empty() {
+                if ::branches::unlikely(self.is_empty()) {
                     None
                 } else {
                     #(
@@ -436,7 +436,7 @@ pub fn derive_mut(input: &Input) -> TokenStream {
             #[doc = #slice_name_str]
             /// ::last_mut()`](https://doc.rust-lang.org/std/primitive.slice.html#method.last_mut).
             pub fn last_mut(&mut self) -> Option<#ref_mut_name> {
-                if self.is_empty() {
+                if ::branches::unlikely(self.is_empty()) {
                     None
                 } else {
                     #(
@@ -454,7 +454,7 @@ pub fn derive_mut(input: &Input) -> TokenStream {
             /// You should use [`Self::reborrow()`] first if you want the
             /// returned values to have a shorter lifetime.
             pub fn split_last_mut(mut self) -> Option<(#ref_mut_name<'a>, #slice_mut_name<'a>)> {
-                if self.is_empty() {
+                if ::branches::unlikely(self.is_empty()) {
                     None
                 } else {
                     #(

soa-derive-internal/src/vec.rs

@@ -196,7 +196,7 @@ pub fn derive(input: &Input) -> TokenStream {
             /// ::insert()`](https://doc.rust-lang.org/std/vec/struct.Vec.html#method.insert).
             #[allow(clippy::forget_non_drop)]
             pub fn insert(&mut self, index: usize, element: #name) {
-                if index >= self.len() {
+                if ::branches::unlikely(index >= self.len()) {
                     panic!("index out of bounds: the len is {} but the index is {}", self.len(), index);
                 }
 
@@ -213,7 +213,7 @@ pub fn derive(input: &Input) -> TokenStream {
             /// Similar to [`std::mem::replace()`](https://doc.rust-lang.org/std/mem/fn.replace.html).
             #[allow(clippy::forget_non_drop)]
             pub fn replace(&mut self, index: usize, element: #name) -> #name {
-                if index >= self.len() {
+                if ::branches::unlikely(index >= self.len()) {
                     panic!("index out of bounds: the len is {} but the index is {}", self.len(), index);
                 }
 
@@ -244,7 +244,7 @@ pub fn derive(input: &Input) -> TokenStream {
             #[doc = #vec_name_str]
             /// ::pop()`](https://doc.rust-lang.org/std/vec/struct.Vec.html#method.pop).
             pub fn pop(&mut self) -> Option<#name> {
-                if self.is_empty() {
+                if ::branches::unlikely(self.is_empty()) {
                     None
                 } else {
                     #(