std::swap(std::basic_fstream) - cppreference.com (original) (raw)

| template< class CharT, class Traits > void swap( basic_fstream<CharT, Traits>& lhs, basic_fstream<CharT, Traits>& rhs ); | | | | ----------------------------------------------------------------------------------------------------------------------------- | | |

Specializes the std::swap algorithm for std::basic_fstream. Exchanges the state of lhs with that of rhs. Effectively calls lhs.swap(rhs).

[edit] Parameters

[edit] Return value

(none)

[edit] Exceptions

May throw implementation-defined exceptions.

[edit] Example

#include #include #include   bool create_stream(std::fstream& fs) { try { std::string some_name = "/tmp/test_file.txt"; std::ios_base::openmode some_flags = fs.trunc; // | other flags   if (std::fstream ts{some_name, some_flags}; ts.is_open()) { std::swap(ts, fs); // stream objects are not copyable => swap return true; } } catch (...) { std::cout << "Exception!\n"; } return false; }   int main() { if (std::fstream fs; create_stream(fs)) { // use fs stream } }

[edit] See also

| | swaps two file streams (public member function) [edit] | | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |