void swap( basic_ifstream& other ); | (since C++11) |
Exchanges the state of the stream with those of other.
This is done by calling basic_istream<CharT, Traits>::swap(other) and rdbuf()->swap(other.rdbuf()).
| other | - | stream to exchange the state with |
(none).
May throw implementation-defined exceptions.
#include <fstream>
#include <iomanip>
#include <iostream>
#include <string>
bool create_stream(std::fstream& fs, const std::string& path) {
try {
std::fstream fst { path, std::ios::trunc | std::ios::in | std::ios::out };
if (fst.is_open()) {
fst.swap( fs );
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"
|
(C++11) | moves the file stream (public member function) |
|
(C++11) | swaps two basic_filebuf objects (public member function of std::basic_filebuf<CharT,Traits>) |
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