C IEEE Standard Packages
The package declarations for the IEEE standard packages are listed in this appendix. The IEEE standards also include package bodies defining the detailed meaning of each of the operators and functions provided by the packages. However, simulator vendors are allowed to substitute accelerated implementations of the packages rather than compiling the package bodies into simulations. The IEEE standards require the packages to be in a resource library named ieee.
The overloaded versions of the xnor operator are not included in the VHDL-87 version of the standard-logic package.
The overloaded versions of the shift, rotate and xnor operators must be commented out of the numeric_bit and numeric_std packages if VHDL-87 compatibility is required.
3.144.33.41