Is there a standard formatting function or operator that will round up? (or down?)

Question

I am using ostringstream to output a number to 2 decimal places as follows

std::ostringstream ostr;

ostr << std::fixed << std::setprecision(2);
ostr << cylinderLength;

So, if cylinderLength = 0.594, the above outputs 0.59 as expected.

Is there an operator or function that will round up or down in the last desired decimal place?

In this case, the above example would print out 0.60 instead.

Answer 1

Try:

// Round towards +infinity (to 1 decimal place (use 100 for 2 decimal places)
ceil(double * 10) / 10


// Round towards -infinity (to 1 decimal place (use 100 for 2 decimal places)
floor(double * 10) / 10