arget type ieee.NUMERIC_STD.UNSIGNED in variable assignment is different from expression type ieee.std_logic_1164.STD_LOGIC_VECTOR code example

Example: Target type ieee.std_logic_1164.STD_LOGIC_VECTOR in variable assignment is different from expression type ieee.std_logic_1164.STD_ULOGIC.

type t_g is array (1 downto 1, 3 downto 1)of integer;
signal g: t_g;