C++核心准则​A.1-A.4：架构理念

A.1: Separate stable code from less stable code

A.1：将稳定代码与不稳定代码分开

Isolating less stable code facilitates its unit testing, interface improvement, refactoring, and eventual deprecation.

隔离不稳定的代码有助于其单元测试，接口改进，重构乃至最终弃用。

A.2: Express potentially reusable parts as a library

A.2：将潜在可重用的部件表示为库

Reason（原因）

Note（注意）

A library is a collection of declarations and definitions maintained, documented, and shipped together. A library could be a set of headers (a "header-only library") or a set of headers plus a set of object files. You can statically or dynamically link a library into a program, or you can #include a header-only library.

库是放在一起维护，记录和发布的声明和定义的集合。一个库可以是一组头文件（“仅头文件的库”）或一组头文件外加一组目标文件。您可以将库静态或动态链接到程序，也可以#include仅包含文件的库。

A.4: There should be no cycles among libraries

A.4：库之间不应存在引用循环

Reason（原因）

• A cycle complicates the build process.
• 循环引用会使编译过程复杂化。
• Cycles are hard to understand and might introduce indeterminism (unspecified behavior).
• 循环很难理解，并且可能引入不确定性（未指定的行为）。

Note（注意）

A library can contain cyclic references in the definition of its components. For example:

库在其组件的定义中可以包含循环引用。例如

???

However, a library should not depend on another that depends on it.

然而，一个库不应该依赖于另一个依赖它的库。

原文链接

https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#a-architectural-ideas