// Diagnostic: a type that contains ITSELF by value has no finite size and must
// be rejected loudly (not infinite-loop the size computation into a crash). A
// pointer payload (`*Tree`) would break the cycle and is the fix the message
// suggests. Covers both source decls and comptime-constructed types — this is
// the source form (regression for issue 0139).
#import "modules/std.sx";

Tree :: enum {
    node: Tree;     // by-VALUE self-reference → infinitely sized
    leaf;
}

main :: () -> i32 {
    t : Tree = .leaf;
    return 0;
}