从编译器设置中关闭 RTTI 有什么好处? [英] What's the advantages of turning off RTTI from compiler setting?

问题描述

由此(RTTI 有多贵?)，似乎很明显动态转换是比静态类型比较昂贵得多，但我想知道在编译器选项(VS2010，/GR-)中关闭 RTTI 选项是否值得

By this(How expensive is RTTI?), it seems clear that dynamic casting is much expensive than static type comparison, but I wonder if it would be worth to turn off RTTI option in compiler option(VS2010, /GR-)

我的代码中没有动态转换(我用静态转换替换了它们).但是 (/GR-) 选项在使用动态转换时除了发出错误之外还有其他作用吗?里面有没有内存或代码优化?

I have no dynamic cast in my code(I replaced them with static cast). But does (/GR-) option do any other than emitting errors when using dynamic cast? Is there any memory or code optimization in there?

提前致谢.

推荐答案

Straight 来自MSDN(强调我的):

Straight from MSDN (emphasis mine):

当/GR 打开时，编译器定义 _CPPRTTI 预处理器宏.默认情况下，/GR 处于打开状态./GR- 禁用运行时类型信息.

When /GR is on, the compiler defines the _CPPRTTI preprocessor macro. By default, /GR is on. /GR- disables run-time type information.

如果编译器无法静态解析代码中的对象类型，请使用/GR.当您的代码使用 dynamic_cast Operator 或 typeid 时，您通常需要/GR 选项.但是，/GR 会增加图像的 .rdata 部分的大小.如果您的代码不使用 dynamic_cast 或 typeid，则/GR- 可能会生成较小的图像.

Use /GR if the compiler cannot statically resolve an object type in your code. You usually need the /GR option when your code uses dynamic_cast Operator or typeid. However, /GR increases the size of the .rdata sections of your image. If your code does not use dynamic_cast or typeid, /GR- may produce a smaller image.

在您的情况下，关闭 RTTI 似乎是值得的.

Looks like turning RTTI off is worth it in your case.

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