std::swap(std::basic_fstream)
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< cpp | io | basic fstream
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swap(std::basic_fstream)
(C++11)
template< class CharT, class Traits >
void swap( basic_fstream<CharT, Traits>& lhs, basic_fstream<CharT, Traits>& rhs );
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
lhs, rhs
-
streams whose state to swap
[edit] Return value
(none)
[edit] Exceptions
May throw implementation-defined exceptions.
[edit] Example
Run this code
#include <fstream> #include <iostream> #include <string> 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 } }