__FB_OPTION_BYVAL__
Intrinsic define (macro value) set by the compiler
Syntax
`
__FB_OPTION_BYVAL__
`
Description
Indicates if parameters to a `Function` or `Sub` are passed by reference as with `ByRef`, or by value as with `ByVal` by default when the by value / by reference specifier is not explicitly stated.
`__FB_OPTION_BYVAL__` is set to non-zero (-1) if by default parameters are passed value, and zero (0) if by default parameters are passed by reference.
The default for passing parameters by reference or by value is determined by the -lang command line option used during compilation or usage of `Option ByVal` in the source file.
Example
`
#if( __FB_OPTION_BYVAL__ <> 0 )
#error Option ByVal must Not be used With This source
#endif
`
Differences from QB

- New to FreeBASIC

See also

- `ByVal`
- `ByRef`
- `Option ByVal`