[I tried to contact the library's author, dietmar.kuehl@claas- solutions.de, but the message bounced back.] Dear Dietmar, I was looking for a better heap class than the one in STL and I was delighted to come across your d_heap class included in the Boost library. Unfortunately, I had a number of problems with it, and I figured you might be interested in some feedback. First, the class didn't compile with VC.NET (and probably won't with VC 6 either). This might be due to non-conformance on the part of Microsoft's compiler and some known limitations with template support, but for some of the issues I think they were due to the non- conformance of the code itself. Second, to my dismay, the code turned out to be seriously flawed. The following simple fragment, for example, causes a crash: THeap::pointer ptrs[10]; ptrs[0] = heap.push(12); ptrs[1] = heap.push(16); heap.remove(ptrs[0]); heap.remove(ptrs[1]); After some debugging and deciphering of the code, I found that the remove() function didn't handle a special case where the node to be 'sifted up' coincided with the last "hole" left in the tree. I think pop() had a similar problem. (In my fixed version, I have expressed pop() in terms of remove(), which resolves the problem and also avoids some code duplication.) I hope some day you get around to publishing an improved version. Another suggestion I have is some way to make sure that the pointer's passed back by client code are valid. Extensive use of assertions throughout the code might also prevent various programming errors. Regards, // Chango V.