From 0523969defcb51df919963bbbd2cd7c4ffc38513 Mon Sep 17 00:00:00 2001
From: Aolin <aolinz@outlook.com>
Date: Wed, 13 Dec 2023 10:06:13 +0800
Subject: [PATCH] wiki: avoid `using namespace std;` in C++ (#53)

---
 website/docs/cpp/cpp-wiki.md | 31 +++++++++++++++++++++++++++++++
 website/sidebars.js          | 10 ++++++++++
 2 files changed, 41 insertions(+)
 create mode 100644 website/docs/cpp/cpp-wiki.md

diff --git a/website/docs/cpp/cpp-wiki.md b/website/docs/cpp/cpp-wiki.md
new file mode 100644
index 0000000..da1aa18
--- /dev/null
+++ b/website/docs/cpp/cpp-wiki.md
@@ -0,0 +1,31 @@
+---
+title: "C++"
+description: "A collection of useful C++ usage and tips."
+---
+
+## Avoid `using namespace std;`
+
+It is common to encounter `using namespace std;` in various C++ sample codes, as it negates the need to prefix `std::` before each standard library object. However, it is not recommended to use it in your code. The reason is that `using namespace std;` might cause name conflicts.
+
+Consider a scenario where you have a function or variable named `max`. If you declare `using namespace std;`, then you will get an error when you try to use `max` because it conflicts with `std::max`.
+
+```cpp
+#include <iostream>
+using namespace std;
+
+int max = 0;
+int main() {
+    cout << max << endl; // error: reference to 'max' is ambiguous
+}
+```
+
+To avoid the preceding error, use the following code instead:
+
+```cpp
+#include <iostream>
+
+int max = 0;
+int main() {
+    std::cout << max << std::endl; // 0
+}
+```
diff --git a/website/sidebars.js b/website/sidebars.js
index a607735..f30f2b5 100644
--- a/website/sidebars.js
+++ b/website/sidebars.js
@@ -45,6 +45,16 @@ const sidebars = {
       ],
     },
     'git-wiki',
+    {
+      type: 'category',
+      label: 'C++',
+      link: {
+        type: 'generated-index',
+      },
+      items: [
+        'cpp/cpp-wiki'
+      ],
+    },
     {
       type: 'category',
       label: 'Python',