有没有办法 std::move std::string 到 std::stringstream

Question

In the c++ reference I do not see a std::stringstream constructor accepting rvalue reference of std::string . Is there any other helper function to move string to stringstream without an overhead or is there a particular reason behind making such limitation?

Answer 1

I do not see a std::stringstream constructor accepting rvalue reference of std::string

That's right. Even the str setter doesn't utilize move semantics, so moving a string into stringstream is not supported (not in the current standard, but hopefully in the next one).

Answer 2

You'll be able to move a string into a string-stream in C++20.

Move semantics are supported by the constructor :

std::string myString{ "..." };
std::stringstream myStream{ std::move(myString) };

It can also be done after construction by calling str() :

std::string myString{ "..." };
std::stringstream myStream;
myStream.str(std::move(myString));