**TL;DR;**
std::move sth will make it into a valid but Unspecified state.
Valid means you can write data into it. Because it still within its lifetime **for just now**.
Unspecified means if you read data, you only get something like `null` or other uncertain state value.
It's more like, you can wirte it , but you shouldn't read it.

**TL;DR;**
Valid means you can write data into it. Because it still within its lifetime **for just now**.
Unspecified means if you read data, you only get something like `null` or other uncertain state value.
It's more like, you could wirte it , but you shouldn't read it.