alignment_of.qbk

来自「Boost provides free peer-reviewed portab」· QBK 代码 · 共 35 行

[/ 
  Copyright 2007 John Maddock.
  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:alignment_of alignment_of]
   template <class T>
   struct alignment_of : public __integral_constant<std::size_t, ALIGNOF(T)> {};
  
__inherit Class template alignment_of inherits from 
`__integral_constant<std::size_t, ALIGNOF(T)>`, where `ALIGNOF(T)` is the
alignment of type T.  

['Note: strictly speaking you should only rely on 
the value of `ALIGNOF(T)` being a multiple of the true alignment of T, although
in practice it does compute the correct value in all the cases we know about.]

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

__examples

[:`alignment_of<int>` inherits from `__integral_constant<std::size_t, ALIGNOF(int)>`.]

[:`alignment_of<char>::type` is the type `__integral_constant<std::size_t, ALIGNOF(char)>`.]

[:`alignment_of<double>::value` is an integral constant 
expression with value `ALIGNOF(double)`.]

[:`alignment_of<T>::value_type` is the type `std::size_t`.]

[endsect]