if case ... where ...{} 报错

var age = 19if case 10...19 = age where age >= 18 
{    
    print(age)
}

抛出异常：Expected ',' joining parts of a multi-clause condition

error: MyPlayground.playground:16:39: error: top-level statement cannot begin with a closure expression

if case 10...19 = age where age >= 18 {

                                ^

如果加上逗号分隔的话：    

if case 10...19 = age , where age >= 18 { print(age) }

Closure expression is unused

error: MyPlayground.playground:16:41: error: top-level statement cannot begin with a closure expression

if case 10...19 = age , where age >= 18 {

                                                               ^