IDA Help: set_numbered_type

Store a type in the til.
'name' may be nullptr for anonymous types.
To replace the existing type use #NTF_REPLACE
     ordinal -  slot number (1...NumberOfLocalTypes), for 0 the new ordinal will be allocated
     name    -  type name
     type    -  serialized type string
     fields  -  serialized type fields
     cmt     -  main type comment
     fldcmts -  serialized type field comments
     sclass  -  type storage class

tinfo_code_t set_numbered_type(
        long ordinal,
        long ntf_flags,
        string name,
        string type,
        string fields="",
        string cmt="",
        string fldcmts="",
        long sclass=0);
#define NTF_REPLACE    0x0004   // replace original type