Visual Studio error C2061: syntax error: identifier

Question

//Species.h
#pragma once
#include <iostream>
#include <string>
using namespace std;
class Species
{
protected:
    int HP, GroundAttack, AirAttack, MoveMode;
public:
};

// Protoss.h
#pragma once
#include "Species.h"
#include "Terran.h"

class Protoss : public Species
{
protected:
    int PS;
public:
    virtual void Input();
    virtual void Output();
    void B_AbilityAttack_A(Terran *);
};

// Terran.h
#pragma once
#include "Species"
#include "Protoss.h"

class Terran : public Species
{
public:
    virtual void Input();
    virtual void Output();
    void A_AbilityAttack_B(Protoss *);
};

"error C2061: syntax error : identifier 'Terran'"

"error C2061: syntax error : identifier 'Protoss'"

error in: void A_AbilityAttack_B(Protoss *) and void B_AbilityAttack_A(Terran *)

如何解决？

修复后在class神族的一个方法中，我写到：

void Protoss::B_AbilityAttack_A(Terran *x)
{
    if (this->AbilityAttack() == 0 && x->GetMoveMode() == 0)
    {
        x->SetHP(x->GetHP() - this->GAttack());
    }
    else if (this->AbilityAttack() == 1 && x->GetMoveMode() == 0)
    {
        x->SetHP(x->GetHP() - this->GAttack());
    }
    else
    {
        x->SetHP(x->GetHP() - this->AAttack());
    }
}

And error in x : "pointer to incomplete class type is not allowed"

那么如何解决呢？

Answer 1

你有循环依赖。删除 Terran 对 Protoss 的包含，反之亦然，改用前向声明。

// Protoss.h
#pragma once
#include "Species.h"

class Terran;
class Protoss : public Species
{
protected:
    int PS;
public:
    virtual void Input();
    virtual void Output();
    void B_AbilityAttack_A(Terran *);
};

// Terran.h
#pragma once
#include "Species"

class Protoss;
class Terran : public Species
{
public:
    virtual void Input();
    virtual void Output();
    void A_AbilityAttack_B(Protoss *);
};

这会起作用，因为您不需要完整的 class 定义，因为参数是指针，您只需要转发声明它们。

Visual Studio error C2061: syntax error: identifier

Visual Studio error C2061: syntax error: identifier

c++

syntax-error

identifier