If variant is negative, then the first negative integer greater than or equal to the variant is returned, otherwise returns the integer portion of the value of variant.
This documentation is based on the MSDN documentation; it appears that this function is either the same as variant_int(), or that there is an error in the MSDN documentation.
As with all the variant arithmetic functions, the parameters for this function
can be either a PHP native type (integer, string, floating point, boolean or
NULL), or an instance of a COM, VARIANT or DOTNET class. PHP native types
will be converted to variants using the same rules as found in the constructor
for the VARIANT class. COM and DOTNET objects
will have the value of their default property taken and used as the variant value.
The variant arithmetic functions are wrappers around the similarly named functions in the COM library; for more information on these functions, consult the MSDN library. The PHP functions are named slightly differently; for example variant_add() in PHP corresponds to VarAdd() in the MSDN documentation.