这种功能非常了不起，但它并不经常起作用，因为通常从运行期数据创建字符串而不是从编译期常量。

This is great when it occurs, but it doesn't help very often because it's much more common to build strings from runtime data than from compile-time constants.

youdao

细节请见保存一个非常量值时的编译期陷阱。

See Compile time trap when saving a non-const value for details.

youdao