std::basic_ios::setstate(3)

NAME
std::basic_ios::setstate - std::basic_ios::setstate

Synopsis
   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
           stream error state flags to set. It can be a combination of the following
           constants:
   state - 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
// Run this code
 #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
   rdstate returns state flags
           (public member function)
   clear modifies state flags
           (public member function)