schmidt%crimee.ics.uci.edu@ORION.CF.UCI.EDU ("Douglas C. Schmidt") (11/28/88)
Hi, There are several rather devious bugs in the libg++ SLList.cc.proto file. The patches below fix those that I've found so far. The major problem is that the assignment operator and the copy in initialization operation fail to work correctly when a list of length 1 is copied, initialized, or passed by value to a function. My fix works correctly, and I'll leave the aesthetic recoding to Doug Lea ;-). Doug Schmidt ---------------------------------------- *** SLList.cc.proto.old Sun Nov 27 14:21:48 1988 --- SLList.cc.proto Sun Nov 27 14:22:58 1988 *************** *** 56,61 **** --- 56,65 ---- <T>SLListNode* p = a.last->tl; <T>SLListNode* h = new <T>SLListNode(p->hd); last = h; + if ( a.last == p ) { // performs correctly for lists of length 1 + last->tl = last; + return; + } p = p->tl; for (;;) { *************** *** 73,79 **** } } ! inline <T>SLList& <T>SLList::operator = (<T>SLList& a) { if (last == a.last) return *this; --- 77,83 ---- } } ! <T>SLList& <T>SLList::operator = (<T>SLList& a) { if (last == a.last) return *this; *************** *** 85,90 **** --- 89,98 ---- <T>SLListNode* p = a.last->tl; <T>SLListNode* h = new <T>SLListNode(p->hd); last = h; + if ( a.last == p ) { + last->tl = last; + return; + } p = p->tl; for (;;) { *************** *** 182,187 **** --- 190,211 ---- return res; } + int <T>SLList::remove_front(<T>& x) + { + if (last == 0) + return 0; + else + { + <T>SLListNode* t = last->tl; + x = t->hd; + if (t == last) + last = 0; + else + last->tl = t->tl; + delete t; + return 1; + } + } void <T>SLList::del_front() {