xcode8 iOS函数返回值使用警告
没有使用返回值时, 警告
swift:
@warn_unused_result func doSomething() -> Bool { return true }
OC:
- (BOOL)doSomething __attribute__((warn_unused_result)) { return YES; }
没有使用返回值时, 不警告
swift:
@discardableResult func doSomething() -> Bool { return true }
OC:
To prevent the compiler from flooding us with warnings when importing Objective-C code the @discardableResult attribute is automatically added for all non-void functions that are not marked with the ((warn_unused_result)) attribute.