The ornamental design for a straight-edge, as shown and described.
FIG. 1 is a top front perspective view of my new, original and ornamental design for a straight-edge;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a rear elevation view thereof;
FIG. 4 is a top elevation view thereof;
FIG. 5 is a bottom elevation view thereof; and,
FIG. 6 is a front end view thereof, the read end view being a mirror image of the front end view.
The broken lines immediately adjacent the shaded areas represent the bounds of the claimed design while all other broken lines are directed to environment and are for illustrative purposes only; the broken lines form no part of the claimed design. The shading lines in the drawings show contour and are not intended to indicate surface ornamentation.