update(cpp-stl): usage of iomanip

issue #104

language/cpp/cppBasicNotes.md

@@ -79,6 +79,8 @@
     - [异常对象的析构](#异常对象的析构)
   - [多态](#多态)
   - [STL](#stl)
+    - [Input Output](#input-output)
+      - [iomanip STL API](#iomanip-stl-api)
     - [Container](#container)
       - [Container Choosing](#container-choosing)
       - [empty/size](#emptysize)
@@ -803,6 +805,31 @@ c.speak("Hello World!") // => "Child: Hello World!"
 
 - 工作方式: copy in, copy out
 
+### Input Output
+
+#### iomanip STL API
+
+output format
+
+```cpp
+#include <iostream>
+#include <iomanip>
+
+int main() {
+    std::cout << "default fill: " << std::setw(10) << 42 << '\n'
+              << "setfill('*'): " << std::setfill('*')
+                                  << std::setw(10) << 42 << '\n';
+
+    std::cout << rd.name << " 0x"
+              << std::setfill('0') << std::setw(16) << std::hex
+              << get_register_value(m_pid, rd.r) << std::endl;
+}
+
+// Output:
+// default fill:         42
+// setfill('*'): ********42
+```
+
 ### Container
 
 - 序列容器: vector string deque list