> you can't turn a C string into a std::string without copying. C and C++ use value semantics by default. std::string is a value., a char* is a reference, so t

> you can't turn a C string into a std::string without copying. C and C++ use value semantics by default. std::string is a value., a char* is a reference, so this shouldn't be surprising. If you want an immutable, zero-copy, drop-in replacement for std::string, use boost::string_ref (a variant of which will soon be standard). It'll give you a memory unsafe (just like a char\) reference to a C string or* a std::string. Want to wrap a C string safely? Use it in combination with unique_ptr or shared_ptr<char> (for exception safety). > Copies of std::string use copy-on-write, Actually that's explicitly forbidden by the standard, since C++11. The interface for std::string always assumed mutation, which made COW really inefficient. > which may create hidden race conditions when sharing data between threads The COW versions of std::string, that I'm aware of at least, were always thread-safe.