return
		}
	}
	check.errorf(rhs0, WrongAssignCount, "assignment mismatch: %s but %s", vars, vals)
}

func (check *Checker) returnError(at poser, lhs []*Var, rhs []*operand) {
	l, r := len(lhs), len(rhs)
	qualifier := "not enough"
	if r > l {
		at = rhs[l] // report at first extra value
		qualifier = "too many"
	} else if r > 0 {

// Otherwise, it is a no-op.
func (a *action) describef(pos poser, format string, args ...interface{}) {
	if debug {
		a.desc = &actionDesc{pos, format, args}
	}
}

// An actionDesc provides information on an action.
// For debugging only.
type actionDesc struct {
	pos    poser
	format string
	args   []interface{}
}

// and x.mode is set to invalid.
func (check *Checker) funcInst(T *target, pos syntax.Pos, x *operand, inst *syntax.IndexExpr, infer bool) ([]Type, []syntax.Expr) {
	assert(T != nil || inst != nil)

	var instErrPos poser
	if inst != nil {
		instErrPos = inst.Pos()
		x.expr = inst // if we don't have an index expression, keep the existing expression of x
	} else {
		instErrPos = pos
	}

		renameSelectorExprs(f, "syntax.Name->ast.Ident", "ident.Value->ident.Name", "ast.Pos->token.Pos") // must happen before renaming identifiers
		renameIdents(f, "syntax->ast", "poser->positioner", "nopos->noposn")
	},
	"array.go":          nil,
	"api_predicates.go": nil,
	"basic.go":          nil,
	"builtins.go": func(f *ast.File) {
		renameImportPath(f, `"cmd/compile/internal/syntax"->"go/ast"`)

				err.addf(arg, "type %s of %s does not match %s (cannot infer %s)", targ, arg.expr, tpar, typeParamsString(tparams))
				return
			}
		}
		smap := makeSubstMap(tparams, targs)
		// TODO(gri): pass a poser here, rather than arg.Pos().
		inferred := check.subst(arg.Pos(), tpar, smap, nil, check.context())
		// CannotInferTypeArgs indicates a failure of inference, though the actual

				err.addf(arg, "type %s of %s does not match %s (cannot infer %s)", targ, arg.expr, tpar, typeParamsString(tparams))
				return
			}
		}
		smap := makeSubstMap(tparams, targs)
		// TODO(gri): pass a poser here, rather than arg.Pos().
		inferred := check.subst(arg.Pos(), tpar, smap, nil, check.context())
		// CannotInferTypeArgs indicates a failure of inference, though the actual