stringbuf, spanbuf : コード例や出力を修正

std::ios_base::app を指定しない限り、書き込み位置の初期値は先頭です。

Author: Raclamusi

reference/spanstream/basic_spanstream/rdbuf.md

@@ -49,7 +49,7 @@ int main()
 ### 出力
 ```
 t
-est!
+!est
 ```
 
 

reference/sstream/basic_stringbuf/op_constructor.md

@@ -129,13 +129,16 @@ int main()
   std::cout << buf1.str() << std::endl;
   
   // (3) 文字列を指定して構築
-  std::stringbuf buf2("initial");
+  std::stringbuf buf2("initial", std::ios_base::out | std::ios_base::app);
   buf2.sputc('!');
   std::cout << buf2.str() << std::endl;
 }
 ```
 * sputc[link /reference/streambuf/basic_streambuf/sputc.md]
 * str()[link str.md]
+* std::ios_base[link /reference/ios/ios_base.md]
+* out[link /reference/ios/ios_base/type-openmode.md]
+* app[link /reference/ios/ios_base/type-openmode.md]
 
 #### 出力
 ```

reference/sstream/basic_stringbuf/str.md

@@ -78,7 +78,7 @@ int main()
   ch = buf.sbumpc();  // 'e'
   std::cout << "3: After reading 2 chars: " << buf.str() << std::endl;
   
-  // 書き込み（現在の位置から）
+  // 書き込み（読み取り位置と書き込み位置は別なので、先頭から書き込まれる）
   buf.sputc('X');
   buf.sputc('Y');
   std::cout << "4: After writing: " << buf.str() << std::endl;
@@ -97,7 +97,7 @@ int main()
 1: Hello, World!
 2: New content
 3: After reading 2 chars: Read/Write test
-4: After writing: ReXY/Write test
+4: After writing: XYad/Write test
 5: Empty? yes
 ```
 

reference/sstream/basic_stringstream/op_constructor.md

@@ -121,12 +121,15 @@ int main()
   std::cout << s << std::endl;
   
   // (3) 文字列を指定して構築
-  std::stringstream ss2("initial value");
+  std::stringstream ss2("initial value", std::ios_base::out | std::ios_base::app);
   ss2 << " added";
   std::cout << ss2.str() << std::endl;
 }
 ```
 * str()[link str.md]
+* std::ios_base[link /reference/ios/ios_base.md]
+* out[link /reference/ios/ios_base/type-openmode.md]
+* app[link /reference/ios/ios_base/type-openmode.md]
 
 #### 出力
 ```

reference/sstream/basic_stringstream/rdbuf.md

@@ -42,5 +42,5 @@ int main()
 ### 出力
 ```
 t
-est!
+!est
 ```

reference/sstream/basic_stringstream/str.md

@@ -67,6 +67,7 @@ int main()
   std::cout << "1: " << ss.str() << std::endl;
   
   // ストリームに追記
+  ss.seekp(0, std::ios_base::end);
   ss << " + added";
   std::cout << "2: " << ss.str() << std::endl;
   
@@ -85,6 +86,9 @@ int main()
   std::cout << "5: Empty? " << (ss.str().empty() ? "yes" : "no") << std::endl;
 }
 ```
+* seekp[link /reference/ostream/basic_ostream/seekp.md]
+* std::ios_base[link /reference/ios/ios_base.md]
+* end[link /reference/ios/ios_base/type-seekdir.md]
 
 #### 出力
 ```