ABAP 7.40: shift val left deleting leading space => shift_left( val = val ) ???

Hi, everybody.

I want to translate the statement

DATA:

   value type char10 value '    X',

   target type char01.

SHIFT value left deleting leading space

target = value(1).

into ABAP 7.40

target = shift_left( val = value....).

But how do I write "deleting leading space" in shift_left? sub = space does not work (due to documentation of shift_left and tests)....