这对你来说可能很明显，但我们尽量使用前向声明，即使它需要写出长命名空间名称) 是/在:

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;
            // ...
        };
    }
}

它也大大减少了在其他编译器上编译的时间.实际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 :)