I have the following abstract class:
class CachedObject: Decodable, Identifiable, Equatable, Hashable {
...
static func cached(id: Int) -> Self? {
// Returns an object from a cache
}
// Load object from the server
static func fetch(id: Int, detail: Int=1, handler: @escaping ((Self?) -> Void)) {
guard id > 0 else {
handler(nil)
return
}
if let object = cached(id: id) {
// The object is in the cache
if object.detail < detail {
// Reload the object
object.reload(detail: detail, handler: handler)
return
}
handler(object as? Self)
return
}
// Do something
}
// Reload existing object
func reload(detail: Int=1, handler: @escaping ((Self?) -> Void)) {
// Do something
}
}
It gives the following warning on the call of object.reload(): Result of call to 'reload(detail:handler:)' is unused But this function returns Void.
If I force it with @discardableResult, I get the following warning: @discardableResult declared on a function returning Void is unnecessary And the previous warning is still here.
I used to silence this warning with: _ = object.reload(detail: detail, handler: handler) But since Swift 5, if I do that, the compiler fails with nonzero exit code, with the following logs:
11. While type-checking expression at [/Users/xxx/Xcode/xxx/Shared/Model/CachedObject.swift:71:17 - line:71:67] RangeText="_ = object.reload(detail: detail, handler: handler" 12. While type-checking-target starting at /Users/xxx/Xcode/xxx/Shared/Model/CachedObject.swift:71:17 Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var LLVM_SYMBOLIZER_PATH to point to it):
Anyone having this issue when using _ = since Swift 5? Note that I also have the same compiler error somewhere else, where I use { _ in } as an argument to a function (I should make another report).
And why does Swift consider that my function reload returns a value and gives me this warning, in the first place?
