Why does gcc warn about incompatible struct assignment with a `self = [super initDesignatedInit];' c
- by gavinbeatty
I have the following base/derived class setup in Objective-C:
@interface ASCIICodeBase : NSObject {
@protected
char code_[4];
}
- (Base *)initWithASCIICode:(const char *)code;
@end
@implementation ASCIICodeBase
- (ASCIICodeBase *)initWithCode:(const char *)code len:(size_t)len {
if (len == 0 || len > 3) {
return nil;
}
if (self = [super init]) {
memset(code_, 0, 4);
strncpy(code_, code, 3);
}
return self;
}
@end
@interface CountryCode : ASCIICodeBase
- (CountryCode *)initWithCode:(const char *)code;
@end
@implementation CountryCode
- (CountryCode *)initWithCode:(const char *)code {
size_t len = strlen(code);
if (len != 2) {
return nil;
}
self = [super initWithCode:code len:len]; // here
return self;
}
@end
On the line marked "here", I get the following gcc warning:
warning: incompatible Objective-C types assigning 'struct ASCIICodeBase *', expected 'struct CurrencyCode *'
Is there something wrong with this code or should I have the ASCIICodeBase return id? Or maybe use a cast on the "here" line?
