From 87eb55a19e45bec5ad203c70fec92d17e77228a1 Mon Sep 17 00:00:00 2001
From: qydysky <qydysky@foxmail.com>
Date: Sun, 28 Jan 2024 16:13:19 +0800
Subject: [PATCH] 1

---
 slice/Slice.go      | 19 +++++++++++++++++++
 slice/Slice_test.go | 27 +++++++++++++++++++++++++++
 2 files changed, 46 insertions(+)

diff --git a/slice/Slice.go b/slice/Slice.go
index 5d98d42..88ccbcc 100644
--- a/slice/Slice.go
+++ b/slice/Slice.go
@@ -159,3 +159,22 @@ func (t *Buf[T]) GetCopyBuf() (buf []T) {
 	copy(buf, t.buf[:t.bufsize])
 	return
 }
+
+func DelFront[S ~[]*T, T any](s S, beforeIndex int) S {
+	return s[:copy(s, s[beforeIndex+1:])]
+}
+
+func AddFront[S ~[]*T, T any](s S, t *T) S {
+	s = append(s, nil)
+	s = s[:1+copy(s[1:], s)]
+	s[0] = t
+	return s
+}
+
+func DelBack[S ~[]*T, T any](s S, fromIndex int) S {
+	return s[:fromIndex]
+}
+
+func AddBack[S ~[]*T, T any](s S, t *T) S {
+	return append(s, t)
+}
diff --git a/slice/Slice_test.go b/slice/Slice_test.go
index a093095..e33d55c 100644
--- a/slice/Slice_test.go
+++ b/slice/Slice_test.go
@@ -3,6 +3,7 @@ package part
 import (
 	"bytes"
 	"testing"
+	"unsafe"
 )
 
 func TestXxx(t *testing.T) {
@@ -79,3 +80,29 @@ func TestXxx2(t *testing.T) {
 		t.Fatal()
 	}
 }
+
+func Test3(t *testing.T) {
+	i := 1
+	var s []*int
+	var p = unsafe.Pointer(&s)
+	s = append(s, &i, &i, &i)
+	if unsafe.Pointer(&s) != p || cap(s) != 3 || len(s) != 3 {
+		t.Fatal()
+	}
+	s = DelFront(s, 2)
+	if unsafe.Pointer(&s) != p || cap(s) != 3 || len(s) != 0 {
+		t.Fatal()
+	}
+	s = AddFront(s, &i)
+	if unsafe.Pointer(&s) != p || cap(s) != 3 || len(s) != 1 {
+		t.Fatal()
+	}
+	s = AddBack(s, &i)
+	if unsafe.Pointer(&s) != p || cap(s) != 3 || len(s) != 2 {
+		t.Fatal()
+	}
+	s = DelBack(s, 1)
+	if unsafe.Pointer(&s) != p || cap(s) != 3 || len(s) != 1 {
+		t.Fatal()
+	}
+}
-- 
2.39.2