[Boost-users] [ptr_container] Why is the key passed to ptr_map by non-const reference?

From: Boris (boriss_at_[hidden])
Date: 2007-09-23 14:53:42

Before anyone refers me to the FAQ at  
http://www.boost.org/libs/ptr_container/doc/faq.html#why-does-ptr-map-t-insert-replace-take-two-arguments-the-key-and-the-pointer-instead-of-one-std-pair-and-why-is-the-key-passed-by-non-const-reference  
- I read it. While it's clear why a reference is used I don't understand  
why it is a *non-const* reference. Any reason why it's not const?

Boris