这听起来很明显，但我们尝试尽可能多地使用向前声明，即使它需要写out长命名空间名称类型是：

It may sound obvious to you, but we try to use forward declarations as much as possible, even if it requires to write out long namespace names the type(s) is/are in:

// Forward declaration stuff
namespace plotter { namespace logic { class Plotter; } }

// Real stuff
namespace plotter {
    namespace samples {
        class Window {
            logic::Plotter * mPlotter;
            // ...
        };
    }
}

它大大减少了编译时间在其他编译器。事实上，它适用于所有配置：）

It greatly reduces the time for compiling also on others compilers. Indeed it applies to all configurations :)