==== round ====

http://www.cplusplus.com/
\\
round() Returns the integral value that is nearest to x, with halfway cases rounded away from zero \\
floor() Rounds x downward, returning the largest integral value that is not greater than x \\
ceil() Rounds x upward, returning the smallest integral value that is not less than x \\
trunc() The nearest integral value that is not larger in magnitude than x (as a floating-point value) \\
\\

^  value^  round^  floor^  ceil^  trunc^
|  2.3|  2.0|  2.0|  3.0|  2.0|
|  3.8|  4.0|  3.0|  4.0|  3.0|
|  5.5|  6.0|  5.0|  6.0|  5.0|
|  -2.3|  -2.0|  -3.0|  -2.0|  -2.0| 
|  -3.8|  -4.0|  -4.0|  -3.0|  -3.0|
|  -5.5|  -6.0|  -6.0|  -5.0|  -5.0|


  * rint() Rounds x to an integral value, using the rounding direction specified by fegetround
  * near() The value of x rounded to a nearby integral (as a floating-point value)