When destroyer guns begin to create a cruiser

What is the value of 5.5-inch guns on French pre-war large destroyers?

They push a destroyer toward cruiser-scale capabilities; guns above five inches, especially 5.9-inch weapons, are a demanding fit for a destroyer.

Guns above five inches are a demanding choice for a destroyer. A 5.5-inch weapon already pushes toward the boundary, while a 5.9-inch gun makes the concern sharper. At that scale, the design begins to pursue cruiser capabilities in destroyer form. The answer is therefore cautious about very large guns on ships still classified as destroyers.