1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
|
[/
Copyright 2020 Glen Joseph Fernandes
(glenjofe@gmail.com)
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:disjunction disjunction]
template<class... T>
struct disjunction;
__inherit Inherits from the first type `U` in the list for which
`bool(U::value)` is `true`, or the last type in the list if there is no such
type. If `sizeof...(T)` is `0` then inherits from `__false_type`.
__header `#include <boost/type_traits/disjunction.hpp>`
[all_compilers] In the absence of variadic-template support, `disjunction` has
only 2 parameters.
__examples
[:Given: `template<int N> struct Int { static const int value = N };` ]
[:`disjunction<>` inherits from `__false_type`.]
[:`disjunction<Int<1> >` inherits from `Int<1>`.]
[:`disjunction<Int<1>, Int<2>, Int<3> >` inherits from `Int<1>`.]
[:`disjunction<Int<0>, Int<2>, Int<3> >` inherits from `Int<2>`.]
[endsect]
|
