c - 为什么我收到 "redefinition of link as different kind of symbol"错误？

Question

我将 link 定义为 struct STnode 指针，但出现错误。错误发生在这个头文件中，这是唯一定义 link 的地方。这是整个头文件

 // Top-down red-black tree header file
 // These will have to change if data in node is more than just an int.
 typedef int Key;
 typedef Key Item;
 #define key(A) (A)
 #define less(A, B) (key(A) < key(B))
 #define eq(A, B) (key(A) == key(B))

 typedef struct STnode* link;

 struct STnode
 {
     Item item;  // Data for this node
     link l, r;  // left & right links
     char red;   // RB color
     int N;      // subtree size
 };

 extern Item NULLitem;

 void STinit();          // Initialize tree with just a sentinel

 Item STsearch(Key v);   // Find node for a key

 Item STselect(int k);   // Treat tree as flattened into an ordered array

 int STinvSelect(Key v); // Inverse of STselect

 void extendedTraceOn(); // Full tracing of intermediate trees

 void basicTraceOn();    // Just trace down and up passes for insert

 void traceOff();        // Run silent

 void STinsert(Item item);     // Insert an item.  No uniqueness check

 void verifyRBproperties();    // Ensure that tree isn't damaged

 void STprintTree();           // Dumps out tree

 void cleanUpUnbalanced(link h);  // Includes subtree sizes and verifies a               
 tree
 // built without balancing

每当我查找 link 最初定义的位置时，它都会将我定向到一个我什至在此代码中未使用的头文件。感谢您提前提供的所有帮助。

编辑:代码后将每个链接更改为STlink。

 // Top-down red-black tree header file
 // These will have to change if data in node is more than just an int.
 typedef int Key;
 typedef Key Item;
 #define key(A) (A)
 #define less(A, B) (key(A) < key(B))
 #define eq(A, B) (key(A) == key(B))

 typedef struct STnode* STlink; // Source

 struct STnode  // Error received - "redefinition of 'STnode' which directs me
                   to source above.
 {
     Item item;  // Data for this node
     STlink l, r;  // left & right links
     char red;   // RB color
     int N;      // subtree size
 };

 extern Item NULLitem;

 void STinit();          // Initialize tree with just a sentinel

 Item STsearch(Key v);   // Find node for a key

 Item STselect(int k);   // Treat tree as flattened into an ordered array

 int STinvSelect(Key v); // Inverse of STselect

 void extendedTraceOn(); // Full tracing of intermediate trees

 void basicTraceOn();    // Just trace down and up passes for insert

 void traceOff();        // Run silent

 void STinsert(Item item);     // Insert an item.  No uniqueness check

 void verifyRBproperties();    // Ensure that tree isn't damaged

 void STprintTree();           // Dumps out tree

 void cleanUpUnbalanced(STlink h);  // Includes subtree sizes and verifies a               
 tree
 // built without balancing

Answer 1

你说:

The error occurs in this header file, and this is the only place where link is defined.

不确定第一个 link 的定义位置，但您可以通过在代码部分使用 STlink 而不是 link 来解决此问题.