Function check_shape_on_expr 

pub fn check_shape_on_expr(
    shape: &dyn Shape,
    cx: &mut Cx,
    expr: &Expr,
) -> Result<ShapeMatch>

Check an expression against a shape, returning the resulting match.

A thin entry point that defers to the shape’s own check_expr; it exists so callers can drive a shape without depending on the Shape trait directly.