doc/is_copy_constructible.qbk

[/ 
  Copyright 2007 John Maddock.
  Copyright 2013 Antony Polukhin.
  Distributed under the Boost Software License, Version 1.0.
  (See accompanying file LICENSE_1_0.txt or copy at
  http://www.boost.org/LICENSE_1_0.txt).
]

[section:is_copy_constructible is_copy_constructible]

   template <class T>
   struct is_copy_constructible : public __tof {};
    
__inherit If `T` is a (possibly cv-qualified) type with a copy constructor,
then inherits from __true_type, otherwise inherits from __false_type.  Type `T`
must be a complete type.

In other words, inherits from __true_type only if copy constructor of `T` not 
marked with `= delete`, `T` does not derives from `boost::noncopyable` and 
does not marked with `BOOST_MOVABLE_BUT_NOT_COPYABLE(T)`.

__compat This trait requires the C++11 features `decltype` and SFINAE-expression support for full support.

If your compiler does not support C++11 deleted functions (`= delete`) or does not support  
SFINAE for the deleted constructors, then derive your classes from `boost::noncopyable` or 
mark them with `BOOST_MOVABLE_BUT_NOT_COPYABLE(T)` to show that class is noncopyable.

The trait does not care about access modifiers, so if you see errors like this:

      'T::T(const T&)' is private
      boost/type_traits/is_copy_constructible.hpp:68:5: error: within this context

then you are trying to call that macro for a structure with private constructor:

      struct T {
          // ...
      private:
          T(const T &);
          // ...
      };

To fix that you must modify your structure, explicitly marking it as noncopyable (`= delete`, 
`boost::noncopyable` or `BOOST_MOVABLE_BUT_NOT_COPYABLE(T)`) or explicitly 
[link boost_typetraits.user_defined specialize trait].


__header ` #include <boost/type_traits/is_copy_constructible.hpp>` or ` #include <boost/type_traits.hpp>`

[endsect]