Q. Why doesn't shared_ptr have template parameters supplying +
Q. Why doesn't shared_ptr have template parameters supplying
traits or policies to allow extensive user customization?
-A. Parameterization discourages users. Shared_ptr is
+A. Parameterization discourages users. Shared_ptr is
carefully crafted to meet common needs without extensive parameterization.
Someday a highly configurable smart pointer may be invented that is also very
easy to use and very hard to misuse. Until then, shared_ptr is the
smart pointer of choice for a wide range of applications. (Those
interested in policy based smart pointers should read Modern
C++ Design by Andrei Alexandrescu.)
Q. Why doesn't shared_ptr use a linked list implementation?
-A. A linked list implementation does not offer enough advantages to
+
Q. Why doesn't shared_ptr use a linked list implementation?
+A. A linked list implementation does not offer enough advantages to
offset the added cost of an extra pointer. See timings
page.
Q. Why don't shared_ptr (and the other Boost smart pointers) +
Q. Why don't shared_ptr (and the other Boost smart pointers)
supply an automatic conversion to T*?
-A. Automatic conversion is believed to be too error prone.
Q. Why does shared_ptr supply use_count()?
+A. As an aid to writing test cases and debugging displays. One of the
+progenitors had use_count(), and it was useful in tracking down bugs in a
+complex project that turned out to have cyclic-dependencies.
Revised 12 July, 2001 +
Revised 13 July, 2001
© Copyright Greg Colvin and Beman Dawes 1999. Permission to copy, use, modify, sell and distribute this document is granted provided this copyright