Differences between sstream and strstream in the C ++ standard library (sstream is recommended)

There are two types of string streams in C ++, one is defined in sstream,
Another type is defined in strstream.
They basically implement the same thing.

Strstream contains
Class strstreambuf;
Class istrstream;
Class ostrstream;
Class strstream;
They are written based on the C-type string char *.

Sstream contains
Class istringstream;
Class ostringstream;
Class stringbuf;
Class stringstream;
Class .......
They are written based on STD: String

Therefore, ostrstream: STR () returns a char * string.
Ostringstream: STR () returns a string of the STD: string type.

Pay attention to the differences between the two. Generally, STD: string is recommended.
Of course, to maintain compatibility with C, using strstream is also a good choice.