在一行上声明多个对象指针会导致编译器错误 [英] Declaring multiple object pointers on one line causes compiler error

问题描述

当我这样做（在我的班级）

  public：
 Entity（）
 { 
 re_sprite_eyes = new sf :: Sprite（）; 
 re_sprite_hair = new sf :: Sprite（）; 
 re_sprite_body = new sf :: Sprite（）; 
} 
 
 private：
 sf :: Sprite * re_sprite_hair; 
 sf :: Sprite * re_sprite_body; 
 sf :: Sprite * re_sprite_eyes; 
  

一切正常。但是，如果我将声明更改为：

  private：
 sf :: Sprite * re_sprite_hair，re_sprite_body，re_sprite_eyes ; 
  

我遇到这个编译错误：

 错误：没有匹配'operator ='in'（（Entity *）this） - > Entity :: re_sprite_eyes =（operator new（272u），（< statement>， sf :: Sprite *）< anonymous>）））
  

c $ c> re_sprite_eyes 是 sf :: Sprite 对象和/或引用。

为什么这不工作？

sf :: Sprite * re_sprite_hair，re_sprite_body，re_sprite_eyes;解决方案

不声明3个指针 - 它是一个指针和2个对象。

sf :: Sprite * 不幸地不适用于所有后面声明的变量，只是第一个。它等效于

  sf :: Sprite * re_sprite_hair; 
 sf :: Sprite re_sprite_body; 
 sf :: Sprite re_sprite_eyes; 
  

您要执行以下操作：

code> sf :: Sprite * re_sprite_hair，* re_sprite_body，* re_sprite_eyes;

您需要为每个变量放一个星。在这种情况下，我更喜欢将星保持在变量的侧面，而不是类型，以使这种情况清楚。

when I do this (in my class)

public:
    Entity()
    {
        re_sprite_eyes = new sf::Sprite();
        re_sprite_hair = new sf::Sprite();
        re_sprite_body = new sf::Sprite();
    }

private:
    sf::Sprite* re_sprite_hair;
    sf::Sprite* re_sprite_body;
    sf::Sprite* re_sprite_eyes;

Everything works fine. However, if I change the declarations to this:

private:
    sf::Sprite* re_sprite_hair, re_sprite_body, re_sprite_eyes;

I get this compiler error:

error: no match for 'operator=' in '((Entity*)this)->Entity::re_sprite_eyes = (operator new(272u), (<statement>, ((sf::Sprite*)<anonymous>)))

And then it says candidates for re_sprite_eyes are sf::Sprite objects and/or references.

Why does this not work? Aren't the declarations the same?

解决方案

sf::Sprite* re_sprite_hair, re_sprite_body, re_sprite_eyes;

Does not declare 3 pointers - it is one pointer and 2 objects.

sf::Sprite* unfortunately does not apply to all the variables declared following it, just the first. It is equivalent to

sf::Sprite* re_sprite_hair;
sf::Sprite re_sprite_body;
sf::Sprite re_sprite_eyes;

You want to do:

sf::Sprite *re_sprite_hair, *re_sprite_body, *re_sprite_eyes;

You need to put one star for each variable. In such cases I prefer to keep the star on the variable's side, rather than the type, to make exactly this situation clear.

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