shift questions (arithmetic and logic)

[Wild Life]

Hello everybody, I have a little question, I know the differences between sll/srl and sla/sra, I need to have a shift arithmetic but sla/sra is only for bitvector types, I have insteade a std_logic_vector type to shift
i also can't use simple concatenation with zeros because I have to shift by a variable (not a constant value)

I could use SHL/SHR operator, this would work but it seemes this operators are good choices for std_logic_vector logical shift, non arithmetic!

Are there ways to use SHL/SHR for having arithmetic shifts? Or, If it's not possible, are there other ways to have them?

Thanx a lot!

 

[TrickyDicky]

you should not be using std_logic_vector for arithmatic. You should be using the signed/unsigned types from the numeric_std library. sll/srl are defined for these types. sla/sra are covered by the resize() function.