Сравнительные объекты-функции поддерживают операции равенства, неравенства, больше, больше или равно, меньше, меньше или равно.
equal_to<string> stringEqual;
sres = stringEqual( sval1, sval2 );
ires = count_if( svec.begin(), svec.end(),
equal_to<string>(), sval1 );
not_equal_to<complex> complexNotEqual;
cres = complexNotEqual( cval1, cval2 );
ires = count_if( svec.begin(), svec.end(),
not_equal_to<string>(), sval1 );
greater<int> intGreater;
ires = intGreater( ival1, ival2 );
ires = count_if( svec.begin(), svec.end(),
greater<string>(), sval1 );
greater_equal<double> doubleGreaterEqual;
dres = doubleGreaterEqual( dval1, dval2 );
ires = count_if( svec.begin(), svec.end(),
greater_equal <string>(), sval1 );
less<Int> IntLess;
Ires = IntLess( Ival1, Ival2 );
ires = count_if( svec.begin(), svec.end(),
less<string>(), sval1 );
less_equal<int> intLessEqual;
ires = intLessEqual( ival1, ival2 );
ires = count_if( svec.begin(), svec.end(),
less_equal<string>(), sval1 );