如何初始化类的静态成员？

Question

我已经写了这段代码。它没有给出编译时错误，但给出运行时错误。你能告诉我这段代码有什么问题吗？

它给出了这个运行时错误->带信息：vpid 1：终止于信号11

    #include <iostream>

    class Color
    {
    public:
        static Color White, Black, Red, Green, Blue;

        unsigned char red, green, blue;

        static void static_Color();

        Color(unsigned char _red
        , unsigned char _green
        , unsigned char _blue)
        : red(_red), green(_green), blue(_blue)
        {
            static_Color();
        }
        
        Color()
        {
            static_Color();
        }
    };
    
    Color Color::White, Color::Black
    , Color::Red, Color::Green, Color::Blue;
    
    void Color::static_Color()
    {
        static bool called_before = false;

        if(called_before)
            return;

        Color::White = Color(255, 255, 255);
        Color::Black = Color(0, 0, 0);
        Color::Red = Color(255, 0, 0);
        Color::Green = Color(0, 255, 0);
        Color::Blue = Color(0, 0, 255);

        called_before = true;
    }
    
    int main()
    {
        std::cout << (int) Color::Red.red;
    }

Answer 1

您不需要

static_Color()

功能。只需使用定义了

static

颜色的正确值初始化它们即可：

class Color {
public:
    static Color White, Black, Red, Green, Blue;

    unsigned char red, green, blue;

    static void static_Color();

    Color(unsigned char _red, unsigned char _green, unsigned char _blue)
        : red(_red), green(_green), blue(_blue) {}

    Color() = default;
};

// Here:
Color Color::White = Color(255, 255, 255);
Color Color::Black = Color(0, 0, 0);
Color Color::Red = Color(255, 0, 0);
Color Color::Green = Color(0, 255, 0);
Color Color::Blue = Color(0, 0, 255);