verify in Fortran Wiki

## Description
Verifies that all the characters in `string` belong to the set of
characters in `set`.
If `back` is either absent or equals `false`, this function returns
the position of the leftmost character of `string` that is not in
`set`. If `back` equals `true`, the rightmost position is returned. If
all characters of `string` are found in `set`, the result is zero.
## Standard
[[Fortran 95]] and later, with `kind` argument [[Fortran 2003]] and later
## Class
Elemental function
## Syntax
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ {: lang=fortran }
result = verify(string, set[, back [, kind]])
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
## Arguments
- `string` - Shall be of type `character`.
- `set` - Shall be of type `character`.
- `back` - (Optional) shall be of type `logical`.
- `kind` - (Optional) An `integer` initialization expression
 indicating the kind parameter of the result.
## Return value
The return value is of type `integer` and of kind `kind`. If `kind` is
absent, the return value is of default integer kind.
## Example
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ {: lang=fortran }
program test_verify
 write(*,*) verify("fortran", "ao") ! 1, found 'f'
 write(*,*) verify("fortran", "foo") ! 3, found 'r'
 write(*,*) verify("fortran", "c++") ! 1, found 'f'
 write(*,*) verify("fortran", "c++", .true.) ! 7, found 'n'
 write(*,*) verify("fortran", "fortran") ! 0' found none
end program
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
## See also
[[scan]]
category: intrinsics