如何将UInt64转换为Int64？

Question

此函数调用的第二个参数：

dispatch_time(DISPATCH_TIME_NOW, NSEC_PER_SEC)

导致编译器错误：

'UInt64' is not convertible to 'Int64'

快速参考：

func dispatch_time(when: dispatch_time_t, delta: Int64) -> dispatch_time_t

var NSEC_PER_SEC: UInt64 { get } /* nanoseconds per second */

Answer 1

请参阅：How do you cast a UInt64 to an Int64?在搜索编译器错误时，该问题无法显示：'UInt64' is not convertible to 'Int64'