As the title says: 

> 
> Does the standard guarantee, that std::string::resize will not do anything, if the new size is the same as the old one?
> 
> 
> 

Of course, I can test it, but it could be UB, so testing will not work here.  

In cppreference.com and cplusplus.com, the doc says nothing about this case

Example:

```
std::string s( "asd" );
// s.size() is 3
s.resize( 3 );    // will this affect **somehow** the string?

```