OBS010 arithmetic-if

warning enabled by default

An arithmetic if (x) l1, l2, l3.

Why

The arithmetic IF branches on the sign of an expression to one of three labels. It was deleted in Fortran 2018. Use a block if / select case.

Reported

if (x) 10, 20, 30

Preferred

if (x < 0) then
  ...
else if (x == 0) then
  ...
end if

Suppressing

For one occurrence, with the reason on the same line (or alone on the line before the statement):

! fobis: ignore[OBS010] <why this occurrence is fine>

For the whole project, ignore = OBS010 in the fobos [lint] section.

Equivalent

Fortitude rule OB081 (see Lint Rules).