Swift: Adding NSLayoutConstraint Issues -

i'm trying create layout constraint between tableview , view controller's view. tableview directly inside main view.

here:

let leftconstant = cgfloat(250.0)   let topconstraint = nslayoutconstraint(item: menutableview,      attribute: .top,      relatedby: .equal,         toitem: self.toplayoutguide,      attribute: .bottom,     multiplier: 1,      constant: 0.0)  let leftconstraint = nslayoutconstraint(item: menutableview,     attribute: .leadingmargin,     relatedby: .equal,        toitem: view,     attribute: .leadingmargin,    multiplier: 1,      constant: -leftconstant)  let bottomconstraint = nslayoutconstraint(item: menutableview,     attribute: .bottom,     relatedby: .equal,        toitem: self.bottomlayoutguide,     attribute: .top,    multiplier: 1,      constant: 0.0)  let widthconstraint = nslayoutconstraint(item: menutableview,     attribute: .width,     relatedby: .equal,        toitem: nil,     attribute: .notanattribute,    multiplier: 0,      constant: leftconstant)  let verticalcenterconstraint = nslayoutconstraint(item: menutableview,     attribute: .centerx,     relatedby: .equal,        toitem: view,     attribute: .centerx,    multiplier: 1,      constant: 0.0)  menutableview.addconstraints([topconstraint, leftconstraint, bottomconstraint, widthconstraint, verticalcenterconstraint]) 

...and i'm getting error:

terminating app due uncaught exception 'nsgenericexception', reason: 'unable install constraint on view.  constraint reference outside subtree of view?  that's illegal. constraint:<nslayoutconstraint:0x16d18490 v:[_uilayoutguide:0x16d24de0]-(0)-[uitableview:0x172a3800]> view:<uitableview: 0x172a3800; frame = (0 0; 250 568); clipstobounds = yes; autoresize = rm+bm; gesturerecognizers = <nsarray: 0x16e23190>; layer = <calayer: 0x16e24e20>; contentoffset: {0, 0}; contentsize: {250, 74}>' 

add constraint of menutableview itself, replace

menutableview.addconstraints([topconstraint, leftconstraint, bottomconstraint, widthconstraint, verticalcenterconstraint]) 

with

menutableview.addconstraint(widthconstraint) 

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and add these constraint view

view.addconstraints([topconstraint, leftconstraint, bottomconstraint]) 

because view holds constraint must ancestor of views constraint involves

**and must choose either .leading or .centerx, otherwise unable simultaneously satisfy constraints.