I am often asked why shared_ptr always uses the custom deleter even when the pointer argument is zero. I know it is safe to delete a NULL pointer so this works with delete but it would seem that if the user is giving a custom deleter, then they are probably doing something else. ie //will crash if fread returns 0 shared_ptr<FILE> foo(fread("foo.txt","r"),fclose); This is an easy screw-up for most new folks and the docs don't really explicitly point out this (I think) non-obvious behavior. One can obviously wrap the deleter with a check among numerous other things but I'm curious what the rationale was since this won't work "out of the box" with C APIs. Can someone point me to the dialog discussing the design decision for this behavior so I can pass it along? Thanks, Mike