std::basic_fstream<CharT,Traits>::swap
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< cpp | io | basic fstream
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basic_fstream::swap
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void swap( basic_fstream& other );
(since C++11)
Exchanges the state of the stream with those of other.
This is done by calling basic_iostream<CharT, Traits>::swap(other) and rdbuf()->swap(other.rdbuf()).
[edit] Parameters
other
-
stream to exchange the state with
[edit] Return value
(none)
[edit] Exceptions
May throw implementation-defined exceptions.
[edit] Example
Run this code
#include <fstream> #include <iomanip> #include <iostream> #include <string> bool create_stream(std::fstream & fs, const std::string & path) { try { std::fstream ts{path, ts.trunc | ts.in | ts.out}; if (ts.is_open()) { ts.swap(fs); // stream objects are not copyable return true; } } catch (...) { std::cout << "Exception!\n"; } return false; } void use_stream(std::fstream & fs) { fs.seekg(0); std::string data; fs >> data; std::cout << "data: " << std::quoted (data) << '\n'; } int main() { std::fstream fs; std::string path = "/tmp/test_file.txt"; if (create_stream(fs, path)) { fs.write(path.c_str(), path.length()); use_stream(fs); } }
Possible output:
data: "/tmp/test_file.txt"