std::basic_ios::setstate

From cppreference.com
< cpplrm; | iolrm; | basic ios
void setstate( iostate state );

Sets the stream error flags state in addition to currently set flags. Essentially calls clear(rdstate() | state). May throw an exception.

Parameters

state - stream error state flags to set. It can be a combination of the following constants:
Constant Explanation
goodbit no error
badbit irrecoverable stream error
failbit input/output operation failed (formatting or extraction error)
eofbit associated input sequence has reached end-of-file


Return value

(none)

Example

#include <iostream>
#include <sstream>

int main()
{
    std::ostringstream stream;

    if (!stream.fail()) {
        std::cout << "stream is not fail\n";
    }

    stream.setstate(std::ios_base::failbit);

    if (stream.fail()) {
        std::cout << "now stream is fail\n";
    }

    if (!stream.good()) {
        std::cout << "and stream is not good\n";
    }
}

Output:

stream is not fail
now stream is fail
and stream is not good

See also

returns state flags
(public member function)
modifies state flags
(public member function)