'.Position'左邊必須有class/struct/union

Question

typedef struct { 
    unsigned short int Position; // << That's what i'm trying to change! 
    unsigned short int OldPosition; 
} Turn_s; 

struct Turn_sMap{ 
    Turn_s *Turn; 
    Turn_sMap *NextTurn; 
}; 

New = new Turn_sMap; 
New->Turn = new Turn_s; 

New->Turn.Position = 0; // Already tried (New->Turn).Position = 0; 

爲什麼我得到那個編譯錯誤？我沒有訪問該結構在結構New中轉而又有一個名爲Position的成員？或者typedef混淆結構類型與一些指針瘋狂？請幫助，我迷路了！ ）：

Answer 1

聲明Turn_s *Turn;，使Turn指針類型。要訪問成員對象，您需要使用->運算符。嘗試：

New->Turn->Position = 0; 

Answer 2

Turn_sMap::Turn是一個指針。您需要取消對它的引用：

New->Turn->Position = 0; 

此外，你不應該在C使用typedef struct ++。剛剛宣佈的結構：

struct Turn_s { 
    unsigned short int Position; // << That's what i'm trying to change! 
    unsigned short int OldPosition; 
}; 

Turn_s a; 
foo(a);