C.45 不要定义仅初始化数据成员的默认构造函数，而应该使用成员初始化器（C++11）

src/widgetImpro.cpp

@@ -0,0 +1,37 @@
+#include <iostream>
+
+class WidgetImpro
+{
+    private:
+        int width{640};
+        int height{480};
+        bool frame{false};
+        bool visible{true};
+
+        int getHeight(const int __width) { return __width * 3 / 4; }
+
+    public:
+        WidgetImpro() = default;
+
+        explicit WidgetImpro(const int __width) noexcept : width(__width), height(getHeight(__width)) {}
+
+        WidgetImpro(const int __width, const int __height) noexcept : width(__width), height(__height) {}
+
+        friend std::ostream & operator<<(std::ostream & __os, const WidgetImpro & __widget)
+        {
+            __os << std::boolalpha << __widget.width << " * " << __widget.height
+                 << ", Frame: " << __widget.frame
+                 << ", Visible: " << __widget.visible;
+
+            return __os;
+        }
+};
+
+int main(int argc, char const *argv[])
+{
+    WidgetImpro wImproVGA;
+
+    std::cout << wImproVGA << '\n';
+
+    return 0;
+}