blob: a1e43bd5cb60ad190b6b1bfb5a1a2d632895f757 [file] [log] [blame]
Brian Silverman4a2409e2018-08-04 23:24:02 -07001[/
2 (C) Copyright 2009-2011 Frederic Bron.
3 Distributed under the Boost Software License, Version 1.0.
4 (See accompanying file LICENSE_1_0.txt or copy at
5 http://www.boost.org/LICENSE_1_0.txt).
6]
7
8[section:has_divides_assign has_divides_assign]
9 template <class Lhs, class Rhs=Lhs, class Ret=dont_care>
10 struct has_divides_assign : public __tof {};
11
12__inherit
13If (i) `lhs` of type `Lhs` and `rhs` of type `Rhs` can be used in expression `lhs/=rhs`,
14and (ii) `Ret=dont_care` or the result of expression `lhs/=rhs` is convertible to `Ret`
15then inherits from __true_type,
16otherwise inherits from __false_type.
17
18The default behaviour (`Ret=dont_care`) is to not check for the return value of binary `operator/=`.
19If `Ret` is different from the default `dont_care` type, the return value is checked to be convertible to `Ret`.
20Convertible to `Ret` means that the return value of the operator can be used as argument to a function expecting `Ret`:
21``
22void f(Ret);
23Lhs lhs;
24Rhs rhs;
25f(lhs/=rhs); // is valid if has_divides_assign<Lhs, Rhs, Ret>::value==true
26``
27If `Ret=void`, the return type is checked to be exactly `void`.
28
29__header `#include <boost/type_traits/has_divides_assign.hpp>` or `#include <boost/type_traits/has_operator.hpp>` or `#include <boost/type_traits.hpp>`
30
31[has_binary_operator_compat]
32
33__examples
34
35[:`has_divides_assign<Lhs, Rhs, Ret>::value_type` is the type `bool`.]
36[:`has_divides_assign<Lhs, Rhs, Ret>::value` is a `bool` integral constant expression.]
37[:`has_divides_assign<int>::value` is a `bool` integral constant expression that evaluates to `true`.]
38[:`has_divides_assign<long>` inherits from `__true_type`.]
39
40[:`has_divides_assign<int, int, int>` inherits from `__true_type`.]
41[:`has_divides_assign<int, int, long>` inherits from `__true_type`.]
42[:`has_divides_assign<int, double, double>` inherits from `__true_type`.]
43[:`has_divides_assign<int, double, int>` inherits from `__true_type`.]
44
45[:`has_divides_assign<const int, int>::value` inherits from `__false_type`.]
46[:`has_divides_assign<int, int, std::string>` inherits from `__false_type`.]
47
48
49[*See also:] [link boost_typetraits.category.value_traits.operators Operator Type Traits]
50
51[binary_operator_known_issues has_divides_assign../=..A&..contains<T>&..[/Nothing]]
52
53[endsect]
54