VHDL extension, it is very good for this aim
File list:
compile_additions
env_c.vhdl
fixed_float_types_c.vhdl
fixed_pkg_c.vhdl
float_pkg_c.vhdl
numeric_std_additions.vhdl
numeric_std_unsigned_c.vhdl
README
standard_additions_c.vhdl
standard_textio_additions_c.vhdl
std_logic_1164_additions.vhdl