rounding_up

Hello everyone!

I noticed, when we parse and validate values (in particular, the int type),
we use the *rint* method, but unfortunately it does not work according to
the round rules. Although on the website
https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/rint-rintf-rintl?view=msvc-170
says something else.

I tested at several OS:

Lubuntu

daria-shanina(at)lnv-dshanina:~/projects/test$ ./rounding_up

rint(2.00) is 2.0 | round(2.00) is 2.0 | ceil(2.00) is 2.0 | floor(2.00) is
2.0

rint(2.10) is 2.0 | round(2.10) is 2.0 | ceil(2.10) is 3.0 | floor(2.10) is
2.0

rint(2.20) is 2.0 | round(2.20) is 2.0 | ceil(2.20) is 3.0 | floor(2.20) is
2.0

rint(2.30) is 2.0 | round(2.30) is 2.0 | ceil(2.30) is 3.0 | floor(2.30) is
2.0

rint(2.40) is 2.0 | round(2.40) is 2.0 | ceil(2.40) is 3.0 | floor(2.40) is
2.0

rint(2.50) is 2.0 | round(2.50) is 3.0 | ceil(2.50) is 3.0 | floor(2.50) is
2.0

rint(2.60) is 3.0 | round(2.60) is 3.0 | ceil(2.60) is 3.0 | floor(2.60) is
2.0

rint(2.70) is 3.0 | round(2.70) is 3.0 | ceil(2.70) is 3.0 | floor(2.70) is
2.0

rint(2.80) is 3.0 | round(2.80) is 3.0 | ceil(2.80) is 3.0 | floor(2.80) is
2.0

rint(2.90) is 3.0 | round(2.90) is 3.0 | ceil(2.90) is 3.0 | floor(2.90) is
2.0

FreeBSD

daria(at)2ndfreebsd:~/projects/test$ ./rounding_up

rint(2.00) is 2.0 | round(2.00) is 2.0 | ceil(2.00) is 2.0 | floor(2.00) is
2.0

rint(2.10) is 2.0 | round(2.10) is 2.0 | ceil(2.10) is 3.0 | floor(2.10) is
2.0

rint(2.20) is 2.0 | round(2.20) is 2.0 | ceil(2.20) is 3.0 | floor(2.20) is
2.0

rint(2.30) is 2.0 | round(2.30) is 2.0 | ceil(2.30) is 3.0 | floor(2.30) is
2.0

rint(2.40) is 2.0 | round(2.40) is 2.0 | ceil(2.40) is 3.0 | floor(2.40) is
2.0

rint(2.50) is 2.0 | round(2.50) is 3.0 | ceil(2.50) is 3.0 | floor(2.50) is
2.0

rint(2.60) is 3.0 | round(2.60) is 3.0 | ceil(2.60) is 3.0 | floor(2.60) is
2.0

rint(2.70) is 3.0 | round(2.70) is 3.0 | ceil(2.70) is 3.0 | floor(2.70) is
2.0

rint(2.80) is 3.0 | round(2.80) is 3.0 | ceil(2.80) is 3.0 | floor(2.80) is
2.0

rint(2.90) is 3.0 | round(2.90) is 3.0 | ceil(2.90) is 3.0 | floor(2.90) is
2.0

Windows

C:\Users\Daria\projects\test>rounding_up.exe

rint(2.00) is 2.0 | round(2.00) is 2.0 | ceil(2.00) is 2.0 | floor(2.00) is
2.0

rint(2.10) is 2.0 | round(2.10) is 2.0 | ceil(2.10) is 3.0 | floor(2.10) is
2.0

rint(2.20) is 2.0 | round(2.20) is 2.0 | ceil(2.20) is 3.0 | floor(2.20) is
2.0

rint(2.30) is 2.0 | round(2.30) is 2.0 | ceil(2.30) is 3.0 | floor(2.30) is
2.0

rint(2.40) is 2.0 | round(2.40) is 2.0 | ceil(2.40) is 3.0 | floor(2.40) is
2.0

rint(2.50) is 2.0 | round(2.50) is 3.0 | ceil(2.50) is 3.0 | floor(2.50) is
2.0

rint(2.60) is 3.0 | round(2.60) is 3.0 | ceil(2.60) is 3.0 | floor(2.60) is
2.0

rint(2.70) is 3.0 | round(2.70) is 3.0 | ceil(2.70) is 3.0 | floor(2.70) is
2.0

rint(2.80) is 3.0 | round(2.80) is 3.0 | ceil(2.80) is 3.0 | floor(2.80) is
2.0

rint(2.90) is 3.0 | round(2.90) is 3.0 | ceil(2.90) is 3.0 | floor(2.90) is
2.0

As you could see in the output, the *round* method works according to the
rules. Maybe we should use it?

Thank you for your attention!

--

Best regards,

Daria Shanina