For the latest documentation on Visual Studio 2017 RC, see Visual Studio 2017 RC Documentation.
warning C28138: The constant argument should instead be variable
This warning is reported in a function call that expects a variable or a non-constant expression, but the call includes a constant. For information about the function and its parameter, consult the WDK documentation of the function.
For example, in the following code example, the parameter of the
READ_PORT_UCHAR macro must be a pointer to the port address, not the address provided as a constant.
The following code example generates this warning message:
To correct this warning, use a pointer to the port address.
There are a few older devices for which a constant parameter is acceptable with the READ_PORT and WRITE_PORT family of functions. When those devices receive this warning, the warning can be suppressed or ignored. However, any new devices should not assume a constant hardware address.