編譯錯誤：左邊模糊不清，右邊模糊

Question

我收到編譯錯誤，說'左'和'右'不明確。

我是否宣佈左，右對錯？

• 內主聲明並沒有幫助
• 移動上述主要功能的定義並不能幫助

如何我會解決這個問題？

最少測試用例：

#include <iostream> 
using namespace std; 
int left = 0, right = 0; 
int main() 
{ 
    cout << left; 
    cout << right; 
} 

所賜：

prog.cpp: In function ‘int main()’: 
prog.cpp:6:13: error: reference to ‘left’ is ambiguous 
prog.cpp:3:5: error: candidates are: int left 
In file included from /usr/include/c++/4.7/ios:43:0, 
       from /usr/include/c++/4.7/ostream:40, 
       from /usr/include/c++/4.7/iostream:40, 
       from prog.cpp:1: 
/usr/include/c++/4.7/bits/ios_base.h:918:3: error: 
      std::ios_base& std::left(std::ios_base&) 
prog.cpp:7:13: error: reference to ‘right’ is ambiguous 
prog.cpp:3:15: error: candidates are: int right 
In file included from /usr/include/c++/4.7/ios:43:0, 
       from /usr/include/c++/4.7/ostream:40, 
       from /usr/include/c++/4.7/iostream:40, 
       from prog.cpp:1: 
/usr/include/c++/4.7/bits/ios_base.h:926:3: error: 
      std::ios_base& std::right(std::ios_base&) 

Answer 1

觀察錯誤消息：

raw.cpp:105: error: reference to ‘right’ is ambiguous 
raw.cpp:5: error: candidates are: int right 
/usr/include/c++/4.2.1/bits/ios_base.h:917: error: 
    std::ios_base& std::right(std::ios_base&) 

它恐嚇閱讀，但基本上這是它說：

raw.cpp:105: error: There's more than one ‘right’ here 
One of them is yours: raw.cpp:5 int right 
Another one isn't: <bits/ios_base.h:917>: some crap in namespace ‘std’ 

因此left和right已在namespace std中定義，您正在導入所有using namespace std。這就是你含糊不清的原因。解決這個問題的最簡單的方法是刪除using namespace std;並添加using std::cin; using std::cout;，但這看起來像是我的口味中的太多全局變量。

順便說一句，你應該把你的代碼併入你的問題。這個問題在這裏可能會比粘貼時間更長，如果沒有人能看到整個問題，我的回答就沒有意義了。