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Merged
apolukhin merged 3 commits into from
Oct 15, 2026
Merged

Implement constexpr boost::any and boost::anys::unique_any #45

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be95c9e
Implement constexpr anys
apolukhin Oct 9, 2026
bf38e06
More tests and fixes
apolukhin Oct 13, 2026
4879c63
add tests with const
apolukhin Oct 14, 2026
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50 changes: 25 additions & 25 deletions include/boost/any.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -58,7 +58,7 @@ BOOST_ANY_BEGIN_MODULE_EXPORT
/// \throws std::bad_alloc or any exceptions arising from the copy
/// constructor of the contained type.
template<typename ValueType>
any(const ValueType & value)
BOOST_ANY_IMPL_CONSTEXPR any(const ValueType & value)
: content(new holder<
typename std::remove_cv<typename std::decay<const ValueType>::type>::type
>(value))
Expand All @@ -77,7 +77,7 @@ BOOST_ANY_BEGIN_MODULE_EXPORT
/// \throws May fail with a `std::bad_alloc`
/// exception or any exceptions arising from the copy
/// constructor of the contained type.
any(const any & other)
BOOST_ANY_IMPL_CONSTEXPR any(const any & other)
: content(other.content ? other.content->clone() : 0)
{
}
Expand All @@ -87,7 +87,7 @@ BOOST_ANY_BEGIN_MODULE_EXPORT
///
/// \post other->empty() is true
/// \throws Nothing.
any(any&& other) noexcept
BOOST_ANY_IMPL_CONSTEXPR any(any&& other) noexcept
: content(other.content)
{
other.content = 0;
Expand All @@ -100,7 +100,7 @@ BOOST_ANY_BEGIN_MODULE_EXPORT
/// \throws std::bad_alloc or any exceptions arising from the move or
/// copy constructor of the contained type.
template<typename ValueType>
any(ValueType&& value
BOOST_ANY_IMPL_CONSTEXPR any(ValueType&& value
, typename std::enable_if<!std::is_same<any&, ValueType>::value >::type* = 0 // disable if value has type `any&`
, typename std::enable_if<!std::is_const<ValueType>::value >::type* = 0) // disable if value has type `const ValueType&&`
: content(new holder< typename std::decay<ValueType>::type >(std::forward<ValueType>(value)))
Expand All @@ -114,7 +114,7 @@ BOOST_ANY_BEGIN_MODULE_EXPORT
/// Releases any and all resources used in management of instance.
///
/// \throws Nothing.
~any() noexcept
BOOST_ANY_IMPL_CONSTEXPR ~any() noexcept
{
delete content;
}
Expand All @@ -125,7 +125,7 @@ BOOST_ANY_BEGIN_MODULE_EXPORT
///
/// \returns `*this`
/// \throws Nothing.
any & swap(any & rhs) noexcept
BOOST_ANY_IMPL_CONSTEXPR any & swap(any & rhs) noexcept
{
placeholder* tmp = content;
content = rhs.content;
Expand All @@ -142,7 +142,7 @@ BOOST_ANY_BEGIN_MODULE_EXPORT
/// or any exceptions arising from the copy constructor of the
/// contained type. Assignment satisfies the strong guarantee
/// of exception safety.
any & operator=(const any& rhs)
BOOST_ANY_IMPL_CONSTEXPR any & operator=(const any& rhs)
{
any(rhs).swap(*this);
return *this;
Expand All @@ -156,7 +156,7 @@ BOOST_ANY_BEGIN_MODULE_EXPORT
///
/// \post `rhs->empty()` is true
/// \throws Nothing.
any & operator=(any&& rhs) noexcept
BOOST_ANY_IMPL_CONSTEXPR any & operator=(any&& rhs) noexcept
{
rhs.swap(*this);
any().swap(rhs);
Expand All @@ -173,7 +173,7 @@ BOOST_ANY_BEGIN_MODULE_EXPORT
/// contained type. Assignment satisfies the strong guarantee
/// of exception safety.
template <class ValueType>
any & operator=(ValueType&& rhs)
BOOST_ANY_IMPL_CONSTEXPR any & operator=(ValueType&& rhs)
{
static_assert(
!anys::detail::is_basic_any<typename std::decay<ValueType>::type>::value,
Expand All @@ -187,13 +187,13 @@ BOOST_ANY_BEGIN_MODULE_EXPORT

/// \returns `true` if instance is empty, otherwise `false`.
/// \throws Nothing.
bool empty() const noexcept
BOOST_ANY_IMPL_CONSTEXPR bool empty() const noexcept
{
return !content;
}

/// \post this->empty() is true
void clear() noexcept
BOOST_ANY_IMPL_CONSTEXPR void clear() noexcept
{
any().swap(*this);
}
Expand All @@ -204,7 +204,7 @@ BOOST_ANY_BEGIN_MODULE_EXPORT
///
/// Useful for querying against types known either at compile time or
/// only at runtime.
const boost::typeindex::type_info& type() const noexcept
BOOST_ANY_IMPL_CONSTEXPR const boost::typeindex::type_info& type() const noexcept
{
return content ? content->type() : boost::typeindex::type_id<void>().type_info();
}
Expand All @@ -223,24 +223,24 @@ BOOST_ANY_BEGIN_MODULE_EXPORT
{
public: // structors

holder(const ValueType & value)
BOOST_ANY_IMPL_CONSTEXPR holder(const ValueType & value)
: held(value)
{
}

holder(ValueType&& value)
BOOST_ANY_IMPL_CONSTEXPR holder(ValueType&& value)
: held(static_cast< ValueType&& >(value))
{
}

public: // queries

const boost::typeindex::type_info& type() const noexcept override
BOOST_ANY_IMPL_CONSTEXPR const boost::typeindex::type_info& type() const noexcept override
{
return boost::typeindex::type_id<ValueType>().type_info();
}

placeholder * clone() const BOOST_OVERRIDE
BOOST_ANY_IMPL_CONSTEXPR placeholder * clone() const BOOST_OVERRIDE
{
return new holder(held);
}
Expand All @@ -255,7 +255,7 @@ BOOST_ANY_BEGIN_MODULE_EXPORT

private: // representation
template<typename ValueType>
friend ValueType * unsafe_any_cast(any *) noexcept;
friend BOOST_ANY_IMPL_CONSTEXPR ValueType * unsafe_any_cast(any *) noexcept;

friend class boost::anys::unique_any;

Expand All @@ -265,7 +265,7 @@ BOOST_ANY_BEGIN_MODULE_EXPORT

/// Exchange of the contents of `lhs` and `rhs`.
/// \throws Nothing.
inline void swap(any & lhs, any & rhs) noexcept
BOOST_ANY_IMPL_CONSTEXPR inline void swap(any & lhs, any & rhs) noexcept
{
lhs.swap(rhs);
}
Expand All @@ -278,15 +278,15 @@ BOOST_ANY_BEGIN_MODULE_EXPORT
// use typeid() comparison, e.g., when our types may travel across
// different shared libraries.
template<typename ValueType>
inline ValueType * unsafe_any_cast(any * operand) noexcept
BOOST_ANY_IMPL_CONSTEXPR inline ValueType * unsafe_any_cast(any * operand) noexcept
{
return std::addressof(
static_cast<any::holder<ValueType> *>(operand->content)->held
);
}

template<typename ValueType>
inline const ValueType * unsafe_any_cast(const any * operand) noexcept
BOOST_ANY_IMPL_CONSTEXPR inline const ValueType * unsafe_any_cast(const any * operand) noexcept
{
return boost::unsafe_any_cast<ValueType>(const_cast<any *>(operand));
}
Expand All @@ -295,7 +295,7 @@ BOOST_ANY_BEGIN_MODULE_EXPORT
/// \returns Pointer to a ValueType stored in `operand`, nullptr if
/// `operand` does not contain specified `ValueType`.
template<typename ValueType>
ValueType * any_cast(any * operand) noexcept
BOOST_ANY_IMPL_CONSTEXPR ValueType * any_cast(any * operand) noexcept
{
return operand && operand->type() == boost::typeindex::type_id<ValueType>()
? boost::unsafe_any_cast<typename std::remove_cv<ValueType>::type>(operand)
Expand All @@ -305,7 +305,7 @@ BOOST_ANY_BEGIN_MODULE_EXPORT
/// \returns Const pointer to a ValueType stored in `operand`, nullptr if
/// `operand` does not contain specified `ValueType`.
template<typename ValueType>
inline const ValueType * any_cast(const any * operand) noexcept
BOOST_ANY_IMPL_CONSTEXPR inline const ValueType * any_cast(const any * operand) noexcept
{
return boost::any_cast<ValueType>(const_cast<any *>(operand));
}
Expand All @@ -314,7 +314,7 @@ BOOST_ANY_BEGIN_MODULE_EXPORT
/// \throws boost::bad_any_cast if `operand` does not contain
/// specified ValueType.
template<typename ValueType>
ValueType any_cast(any & operand)
BOOST_ANY_IMPL_CONSTEXPR ValueType any_cast(any & operand)
{
using nonref = typename std::remove_reference<ValueType>::type;

Expand Down Expand Up @@ -346,7 +346,7 @@ BOOST_ANY_BEGIN_MODULE_EXPORT
/// \throws boost::bad_any_cast if `operand` does not contain
/// specified `ValueType`.
template<typename ValueType>
inline ValueType any_cast(const any & operand)
BOOST_ANY_IMPL_CONSTEXPR inline ValueType any_cast(const any & operand)
{
using nonref = typename std::remove_reference<ValueType>::type;
return boost::any_cast<const nonref &>(const_cast<any &>(operand));
Expand All @@ -356,7 +356,7 @@ BOOST_ANY_BEGIN_MODULE_EXPORT
/// \throws boost::bad_any_cast if `operand` does not contain
/// specified `ValueType`.
template<typename ValueType>
inline ValueType any_cast(any&& operand)
BOOST_ANY_IMPL_CONSTEXPR inline ValueType any_cast(any&& operand)
{
static_assert(
std::is_rvalue_reference<ValueType&&>::value /*true if ValueType is rvalue or just a value*/
Expand Down
12 changes: 12 additions & 0 deletions include/boost/any/detail/config.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,18 @@
#ifndef BOOST_ANY_ANYS_DETAIL_CONFIG_HPP
#define BOOST_ANY_ANYS_DETAIL_CONFIG_HPP

#if defined __has_include
# if __has_include (<version>)
# include <version>
# endif
#endif

#if defined(__cpp_lib_constexpr_new) || defined(BOOST_ANY_DOXYGEN_INVOKED)
#define BOOST_ANY_IMPL_CONSTEXPR constexpr
#else
#define BOOST_ANY_IMPL_CONSTEXPR
#endif

#ifdef BOOST_ANY_INTERFACE_UNIT
# define BOOST_ANY_BEGIN_MODULE_EXPORT export {
# define BOOST_ANY_END_MODULE_EXPORT }
Expand Down
4 changes: 2 additions & 2 deletions include/boost/any/detail/placeholder.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -27,8 +27,8 @@ namespace detail {

class BOOST_SYMBOL_VISIBLE placeholder {
public:
virtual ~placeholder() {}
virtual const boost::typeindex::type_info& type() const noexcept = 0;
BOOST_ANY_IMPL_CONSTEXPR virtual ~placeholder() {}
BOOST_ANY_IMPL_CONSTEXPR virtual const boost::typeindex::type_info& type() const noexcept = 0;
};

} // namespace detail
Expand Down
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