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Andrzej Krzemienski
2022-06-22 22:59:18 +02:00
parent 4ead6d14ff 938806c876
commit 3038bdea4b
9 changed files with 174 additions and 11 deletions
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2
doc/00_optional.qbk
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@ -2,7 +2,7 @@
[quickbook 1.4]
[authors [Cacciola Carballal, Fernando Luis]]
[copyright 2003-2007 Fernando Luis Cacciola Carballal]
[copyright 2014-2021 Andrzej Krzemieński]
[copyright 2014-2022 Andrzej Krzemieński]
[category miscellaneous]
[id optional]
[dirname optional]

18
doc/23_ref_optional_io.qbk
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@ -26,11 +26,11 @@ template <class CharType, class CharTrait, class T>
template <class CharType, class CharTrait>
std::basic_ostream<CharType, CharTrait>&
operator<<(std::basic_ostream<CharType, CharTrait>& out, none_t const&); ``[link reference_operator_ostream_none __GO_TO__]``
template<class CharType, class CharTrait, class T>
std::basic_istream<CharType, CharTrait>&
operator>>(std::basic_istream<CharType, CharTrait>& in, optional<T>& v); ``[link reference_operator_istream __GO_TO__]``
} // namespace boost
```
@ -43,8 +43,8 @@ template<class CharType, class CharTrait, class T>
`template <class CharType, class CharTrait, class T>` [br]
\u00A0\u00A0\u00A0\u00A0`std::basic_ostream<CharType, CharTrait>&` [br]
\u00A0\u00A0\u00A0\u00A0`operator<<(std::basic_ostream<CharType, CharTrait>& out, optional<T> const& v);`
std::basic_ostream<CharType, CharTrait>&` [br]
operator<<(std::basic_ostream<CharType, CharTrait>& out, optional<T> const& v);`
* [*Effect:] Outputs an implementation-defined string. The output contains the information about whether the optional object contains a value or not. If `v` contains a value, the output contains result of calling `out << *v`.
* [*Returns:] `out`.
@ -53,8 +53,8 @@ __SPACE__
[#reference_operator_ostream_none]
`template <class CharType, class CharTrait, class T>` [br]
\u00A0\u00A0\u00A0\u00A0`std::basic_ostream<CharType, CharTrait>&` [br]
\u00A0\u00A0\u00A0\u00A0`operator<<(std::basic_ostream<CharType, CharTrait>& out, none_t);`
std::basic_ostream<CharType, CharTrait>&` [br]
operator<<(std::basic_ostream<CharType, CharTrait>& out, none_t);`
* [*Effect:] Outputs an implementation-defined string.
* [*Returns:] `out`.
@ -63,11 +63,11 @@ __SPACE__
[#reference_operator_istream]
`template <class CharType, class CharTrait, class T>` [br]
\u00A0\u00A0\u00A0\u00A0`std::basic_ostream<CharType, CharTrait>&` [br]
\u00A0\u00A0\u00A0\u00A0`operator>>(std::basic_istream<CharType, CharTrait>& in, optional<T>& v);`
std::basic_ostream<CharType, CharTrait>&` [br]
operator>>(std::basic_istream<CharType, CharTrait>& in, optional<T>& v);`
* [*Requires:] `T` is __SGI_DEFAULT_CONSTRUCTIBLE__ and __MOVE_CONSTRUCTIBLE__.
* [*Effect:] Reads the value of optional object from `in`. If the string representation indicates that the optional object should contain a value, `v` contains a value and its contained value is obtained as if by default-constructing an object `o` of type `T` and then calling `in >> o`; otherwise `v` does not contain a value, and the previously contained value (if any) has been destroyed.
* [*Effect:] Reads the value of optional object from `in`. If the string representation indicates that the optional object should contain a value, `v` contains a value and its contained value is obtained as if by default-constructing an object `o` of type `T` and then calling `in >> o`; otherwise `v` does not contain a value, and the previously contained value (if any) has been destroyed.
* [*Returns:] `out`.
[endsect]

10
doc/27_ref_optional_synopsis.qbk
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@ -73,6 +73,16 @@
} // namespace boost
namespace std {
template <typename T>
struct hash<boost::optional<T> > ; ``[link reference_std_hash_spec __GO_TO__]``
template <typename T>
struct hash<boost::optional<T&> > ; ``[link reference_std_hash_spec __GO_TO__]``
} // namespace std
[endsect]

34
doc/28_ref_optional_semantics.qbk
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@ -1408,3 +1408,37 @@ assert (addressof(*opt0) == addressof(y));
``
[endsect]
[section Detailed Semantics - std::hash Specializations]
__SPACE__
[#reference_std_hash_spec]
``
namespace std {
template <typename T>
struct hash<boost::optional<T> > ;
template <typename T>
struct hash<boost::optional<T&> > ;
} // namespace std
``
The specialization `hash<optional<T>>` is enabled if and only if
`hash<remove_­const_­t<T>>` is enabled. When enabled, for an object `o`
of type `optional<T>`, if `o.has_­value() == true`, then `hash<optional<T>>()(o)`
evaluates to the same value as `hash<remove_­const_­t<T>>()(*o)`; otherwise it
evaluates to an unspecified value.
The member functions are not guaranteed to be `noexcept`.
[caution
You may get compiler errors when your program provides specializations for
`std::hash<boost::optional<T>>`. If this happens, define macro
`BOOST_OPTIONAL_CONFIG_DO_NOT_SPECIALIZE_STD_HASH` to suppress the specializations
of `std::hash` in this library.
]
[endsect]

6
doc/91_relnotes.qbk
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@ -1,7 +1,7 @@
[/
Boost.Optional
Copyright (c) 2015 - 2021 Andrzej Krzemienski
Copyright (c) 2015 - 2022 Andrzej Krzemienski
Distributed under the Boost Software License, Version 1.0.
(See accompanying file LICENSE_1_0.txt or copy at
@ -11,6 +11,10 @@
[section:relnotes Release Notes]
[heading Boost Release 1.80]
* [*Breaking change:] Added specializations for `std::hash<boost::opitonal<T>>`. This fixes [@https://github.com/boostorg/optional/issues/55 issue #55]. You may get compiler errors when your program provides specializations for `std::hash<boost::optional<T>>`. If this happens, define macro `BOOST_OPTIONAL_CONFIG_DO_NOT_SPECIALIZE_STD_HASH` to suppress the specializations of `std::hash` in this library.
[heading Boost Release 1.79]
* Fixed [@https://github.com/boostorg/optional/issues/98 issue #98].