John Maddock wrote:
Which const?
From-type. The compiler complained about the fact that there are only non-const-argument constructors in auto_ptr: Error : function call '[std::auto_ptr<const foo *>].auto_ptr({lval} const std::auto_ptr<const foo *>)' does not match 'std::auto_ptr<const foo *>::auto_ptr(const foo **) throw()' (explicit) 'std::auto_ptr<const foo *>::auto_ptr(std::auto_ptr<const foo *> &) throw()' 'std::auto_ptr<const foo *>::auto_ptr<typename __T0>(std::auto_ptr<__T1_0> &) throw()' 'std::auto_ptr<const foo *>::auto_ptr(std::auto_ptr_ref<const foo *>) throw()'
The only case I can think of is along the lines of:
class foo { public: foo(bar&); };
is_convertible<bar,foo>::value should be true. is_convertible<const bar,foo>::value should be false.
I see ... that would of course change the semantics. stefan