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forked from Alepha/Alepha

Beginnings of support for default_lens.

The `default_lens` would be used for anything and everything.
And `tuplizeAggregate` can then be used to make a defaulted
`default_lens`.  This simplifies most lens oriented code, as
I move forward.
This commit is contained in:
2021-12-03 01:47:44 -05:00
parent 5f15b0ee38
commit 7de08953c8
3 changed files with 72 additions and 21 deletions

View File

@ -4,6 +4,8 @@ static_assert( __cplusplus > 2017, "C++17 Required" );
#include <Alepha/Alepha.h>
#include <type_traits>
namespace Alepha::Hydrogen::Meta
{
inline namespace exports { inline namespace type_value_wrapper {} }

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@ -15,7 +15,30 @@ namespace Alepha::Hydrogen::Reflection
namespace detail::tuplize_aggregate
{
inline namespace exports
inline namespace exports {}
template< typename T, typename= void >
struct has_salient_members_constant : std::false_type {};
template< typename T >
struct has_salient_members_constant< T, std::void_t< decltype( T::salient_members ) > >
: std::true_type {};
template< typename T >
constexpr bool has_salient_members_constant_v= has_salient_members_constant< T >::value;
template< typename T >
constexpr std::size_t
compute_salient_members_count_impl()
{
if constexpr( has_salient_members_constant_v< T > ) return T::salient_members;
else return aggregate_member_count_v< std::decay_t< T > >;
}
template< typename T >
constexpr std::size_t compute_salient_members_count_v= compute_salient_members_count_impl< T >();
namespace exports
{
/*!
* Deconstruct an aggregate object into a tie-based tuple pointing at its members.
@ -170,7 +193,7 @@ namespace Alepha::Hydrogen::Reflection
constexpr decltype( auto )
tuplizeAggregate( Aggregate &&agg )
{
return tuplizeAggregate< aggregate_member_count_v< std::decay_t< Aggregate > > >( std::forward< Aggregate >( agg ) );
return tuplizeAggregate< compute_salient_members_count_v< std::decay_t< Aggregate > > >( std::forward< Aggregate >( agg ) );
}
}
}

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@ -6,9 +6,12 @@ static_assert( __cplusplus > 201700, "C++17 Required" );
#include <type_traits>
#include <Alepha/Meta/overload.h>
#include <Alepha/Meta/dep_value.h>
#include <Alepha/Capabilities.h>
#include <Alepha/Meta/overload.h>
namespace Alepha::Hydrogen
{
@ -20,12 +23,8 @@ namespace Alepha::Hydrogen
using namespace Meta::exports::template_overload;
// Basic capability support
// TODO: non-base-type capability via ADL rules on templates.
struct comparable {};
namespace exports
{
using detail::comparisons::comparable;
@ -74,6 +73,14 @@ namespace Alepha::Hydrogen
template< typename T >
constexpr bool supports_spaceship_lens_v= supports_spaceship_lens< T >::value;
template< typename T >
constexpr decltype( auto )
make_spaceship_lens( T &t )
{
if constexpr( supports_spaceship_lens_v< T > ) return spaceship_lens( t );
//else if constexpr( supports_default_lens_v< T > ) return default_lens( t );
else static_assert( Meta::dep_value< false, T > );
}
// Value lens support
@ -121,6 +128,15 @@ namespace Alepha::Hydrogen
template< typename T >
constexpr bool supports_value_lens_v= supports_value_lens< T >::value;
template< typename T >
constexpr decltype( auto )
make_value_lens( T &t )
{
if constexpr( supports_value_lens_v< T > ) return value_lens( t );
//else if constexpr( supports_default_lens_v< T > ) return default_lens( t );
else static_assert( Meta::dep_value< false, T > );
}
// Equality Lens support
template< typename T, typename= void >
@ -167,6 +183,14 @@ namespace Alepha::Hydrogen
template< typename T >
constexpr bool supports_equality_lens_v= supports_equality_lens< T >::value;
template< typename T >
constexpr decltype( auto )
make_equality_lens( T &t )
{
if constexpr( supports_equality_lens_v< T > ) return equality_lens( t );
//else if constexpr( supports_default_lens_v< T > ) return default_lens( t );
else static_assert( Meta::dep_value< false, T > );
}
// Strict weak order lens support
@ -186,7 +210,7 @@ namespace Alepha::Hydrogen
typename= std::enable_if_t< has_strict_weak_order_lens_member_v< T > >,
overload< __LINE__ > = nullptr
>
decltype( auto )
constexpr decltype( auto )
strict_weak_order_lens( T &t )
{
return t.strict_weak_order_lens();
@ -199,7 +223,7 @@ namespace Alepha::Hydrogen
typename= std::enable_if_t< supports_value_lens_v< T > >,
overload< __LINE__ > = nullptr
>
decltype( auto )
constexpr decltype( auto )
strict_weak_order_lens( T &t )
{
return value_lens( t );
@ -214,84 +238,86 @@ namespace Alepha::Hydrogen
template< typename T >
constexpr bool supports_strict_weak_order_lens_v= supports_strict_weak_order_lens< T >::value;
template< typename T >
constexpr decltype( auto )
make_strict_weak_order_lens( T &t )
{
if constexpr( supports_strict_weak_order_lens_v< T > ) return strict_weak_order_lens( t );
//else if constexpr( supports_default_lens_v< T > ) return default_lens( t );
else static_assert( Meta::dep_value< false, T > );
}
// Operator support:
template
<
typename T,
typename= std::enable_if_t< has_comparable_capability_v< T > >,
typename= std::enable_if_t< supports_equality_lens_v< T > >,
overload< __LINE__ > = nullptr
>
constexpr bool
operator == ( const T &lhs, const T &rhs )
{
return equality_lens( lhs ) == equality_lens( rhs );
return make_equality_lens( lhs ) == make_equality_lens( rhs );
}
template
<
typename T,
typename= std::enable_if_t< has_comparable_capability_v< T > >,
typename= std::enable_if_t< supports_equality_lens_v< T > >,
overload< __LINE__ > = nullptr
>
constexpr bool
operator != ( const T &lhs, const T &rhs )
{
return equality_lens( lhs ) != equality_lens( rhs );
return make_equality_lens( lhs ) != make_equality_lens( rhs );
}
template
<
typename T,
typename= std::enable_if_t< has_comparable_capability_v< T > >,
typename= std::enable_if_t< supports_strict_weak_order_lens_v< T > >,
overload< __LINE__ > = nullptr
>
constexpr bool
operator < ( const T &lhs, const T &rhs )
{
return strict_weak_order_lens( lhs ) < strict_weak_order_lens( rhs );
return make_strict_weak_order_lens( lhs ) < make_strict_weak_order_lens( rhs );
}
template
<
typename T,
typename= std::enable_if_t< has_comparable_capability_v< T > >,
typename= std::enable_if_t< supports_strict_weak_order_lens_v< T > >,
overload< __LINE__ > = nullptr
>
constexpr bool
operator > ( const T &lhs, const T &rhs )
{
return strict_weak_order_lens( lhs ) > strict_weak_order_lens( rhs );
return make_strict_weak_order_lens( lhs ) > make_strict_weak_order_lens( rhs );
}
template
<
typename T,
typename= std::enable_if_t< has_comparable_capability_v< T > >,
typename= std::enable_if_t< supports_strict_weak_order_lens_v< T > >,
overload< __LINE__ > = nullptr
>
constexpr bool
operator <= ( const T &lhs, const T &rhs )
{
return strict_weak_order_lens( lhs ) <= strict_weak_order_lens( rhs );
return make_strict_weak_order_lens( lhs ) <= make_strict_weak_order_lens( rhs );
}
template
<
typename T,
typename= std::enable_if_t< has_comparable_capability_v< T > >,
typename= std::enable_if_t< supports_strict_weak_order_lens_v< T > >,
overload< __LINE__ > = nullptr
>
constexpr bool
operator >= ( const T &lhs, const T &rhs )
{
return strict_weak_order_lens( lhs ) >= strict_weak_order_lens( rhs );
return make_strict_weak_order_lens( lhs ) >= make_strict_weak_order_lens( rhs );
}
template< typename ... Args >