std::iostream_category

Defined in header <ios>
const std::error_category& iostream_category();		(since C++11)

Obtains a reference to the static error category object for iostream errors. The object is required to override the virtual function error_category::name() to return a pointer to the string "iostream". It is used to identify error codes provided in the exceptions of type std::ios_base::failure.

Parameters

(none)

Return value

a reference to the static object of unspecified runtime type, derived from std::error_category.

Example

run this code

#include <iostream>
#include <fstream>
int main()
{
    std::ifstream f("doesn't exist");
    try {
        f.exceptions(f.failbit);
    } catch (const std::ios_base::failure& e) {
        std::cout << "Caught an ios_base::failure.\n"
                  << "Error category: " << e.code().category().name() << '\n';
    }
}

Output:

Caught an ios_base::failure.
Error category: iostream

See also

failure	stream exception (public member class of std::ios_base)
io_errc (C++11)	the IO stream error codes (enum)
error_category (C++11)	base class for error categories (class)