This is hardly newsworthy. If the extensions were called ‘Jabberwocky C Extennsions’ no one would have cared. The extension allows for tagged unnamed structs inside of a struct, e.g.:
struct inner { /* ... */ }; struct outer { int value; struct inner; };Untagged?
You mean ‘unnamed’ is what’s confusing you?
Normally you can do anonymous struct/union members or struct struct/union members that are tagged structs but not anonymous.
I.e. in standard C you’d have to do either:
struct foo { int baz; }; struct bar { struct foo foo; }; ... struct bar data; data.foo.baz = 0;or:
struct bar { struct { int baz; } foo; }; ... struct bar data; data.baz = 0;but to do the following, you’d need the extension:
struct foo { int baz; }; struct bar { struct foo; }; ... struct bar data; data.baz = 0;Minor correction: Unnamed structs and unions (so your second example) are not part of C. They are GNU extensions.
“ANSI C” by Kernighan and Ritchie disagrees , including that syntax (note : retranslation from Polish as that’s the language my copy is in) :
A8.3
[…]
struct-union-specifier:
, union-struct identifier ₒₚₜ{compound-declaration-list}
, union-struct identifier[…]
Specifiers of structures or unions with [a compound declaration] list, but with no label [identifier], creates a unique type; it may only be referred to in the declaration in which it is part.
Tag is what goes after the
structkeyword to allow referring to the struct type. Structs don’t have to have a tag. Name is what field are called. Adapting Obin’s example:struct foo { int baz; }; struct bar { struct foo qux; }; struct bar data; data.qux.baz = 0;fooandbarare tags forstruct fooandstruct bartypes respectively;bazandquxare field names; anddatais a variable name.
If I understood correctly, it’s free software anyway, so why the discussion?
Because they wanted drama and clickbaity headline.
…Extend
