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Diffstat (limited to '3rd_party/include/opentracing/expected/expected.hpp')
| -rw-r--r-- | 3rd_party/include/opentracing/expected/expected.hpp | 1245 |
1 files changed, 1245 insertions, 0 deletions
diff --git a/3rd_party/include/opentracing/expected/expected.hpp b/3rd_party/include/opentracing/expected/expected.hpp new file mode 100644 index 0000000..8283a77 --- /dev/null +++ b/3rd_party/include/opentracing/expected/expected.hpp @@ -0,0 +1,1245 @@ +// Copyright (C) 2016 Martin Moene. +// +// This version targets C++11 and later. +// +// This code is licensed under the MIT License (MIT). +// +// expected lite is based on: +// A proposal to add a utility class to represent expected monad - Revision 2 +// by Vicente J. Botet Escriba and Pierre Talbot. + +#ifndef OPENTRACING_EXPECTED_LITE_HPP +#define OPENTRACING_EXPECTED_LITE_HPP + +#include <cassert> +#include <exception> +#include <functional> +#include <initializer_list> +#include <new> +#include <stdexcept> +#include <type_traits> +#include <utility> +#include <opentracing/version.h> + +#define expected_lite_VERSION "0.0.0" + +// Compiler detection: + +#define nsel_CPP11_OR_GREATER ( __cplusplus >= 201103L ) +#define nsel_CPP14_OR_GREATER ( __cplusplus >= 201402L ) + +#if nsel_CPP14_OR_GREATER +# define nsel_constexpr14 constexpr +#else +# define nsel_constexpr14 /*constexpr*/ +#endif + +// Method enabling + +#define nsel_REQUIRES(...) \ + typename std::enable_if<__VA_ARGS__, void*>::type = 0 + +#define nsel_REQUIRES_0(...) \ + template< bool B = (__VA_ARGS__), typename std::enable_if<B, int>::type = 0 > + +#define nsel_REQUIRES_T(...) \ + typename = typename std::enable_if< (__VA_ARGS__), opentracing::expected_detail::enabler >::type + +namespace opentracing { +BEGIN_OPENTRACING_ABI_NAMESPACE + +template< typename T, typename E > +class expected; + +namespace expected_detail { + +/// for nsel_REQUIRES_T + +enum class enabler{}; + +/// discriminated union to hold value or 'error'. + +template< typename T, typename E > +union storage_t +{ + friend class expected<T,E>; + +private: + typedef T value_type; + typedef E error_type; + + // no-op construction + storage_t() {} + ~storage_t() {} + + void construct_value( value_type const & v ) + { + new( &m_value ) value_type( v ); + } + + void construct_value( value_type && v ) + { + new( &m_value ) value_type( std::forward<T>( v ) ); + } + + void destruct_value() + { + m_value.~value_type(); + } + + void construct_error( error_type const & e ) + { + new( &m_error ) error_type( e ); + } + + void construct_error( error_type && e ) + { + new( &m_error ) error_type( std::move( e ) ); + } + + void destruct_error() + { + m_error.~error_type(); + } + + constexpr value_type const & value() const & + { + return m_value; + } + + value_type & value() & + { + return m_value; + } + + constexpr value_type && value() const && + { + return std::move( m_value ); + } + + const value_type * value_ptr() const + { + return &m_value; + } + + value_type * value_ptr() + { + return &m_value; + } + + error_type const & error() const + { + return m_error; + } + + error_type & error() + { + return m_error; + } + +private: + value_type m_value; + error_type m_error; +}; + +/// discriminated union to hold only 'error'. + +template< typename E > +union storage_t<void, E> +{ + friend class expected<void,E>; + +private: + typedef void value_type; + typedef E error_type; + + // no-op construction + storage_t() {} + ~storage_t() {} + + void construct_error( error_type const & e ) + { + new( &m_error ) error_type( e ); + } + + void construct_error( error_type && e ) + { + new( &m_error ) error_type( std::move( e ) ); + } + + void destruct_error() + { + m_error.~error_type(); + } + + error_type const & error() const + { + return m_error; + } + + error_type & error() + { + return m_error; + } + +private: + error_type m_error; +}; + +} // namespace expected_detail + +/// class unexpected_type + +template< typename E = std::error_code > +class unexpected_type +{ +public: + typedef E error_type; + + unexpected_type() = delete; + + nsel_REQUIRES_0( + std::is_copy_constructible<error_type>::value ) + + constexpr explicit unexpected_type( error_type const & error ) + : m_error( error ) + {} + + nsel_REQUIRES_0( + std::is_move_constructible<error_type>::value ) + + constexpr explicit unexpected_type( error_type && error ) + : m_error( std::move( error ) ) + {} + + constexpr error_type const & value() const + { + return m_error; + } + + error_type & value() + { + return m_error; + } + +private: + error_type m_error; +}; + +/// class unexpected_type, std::exception_ptr specialization + +template<> +class unexpected_type< std::exception_ptr > +{ +public: + typedef std::exception_ptr error_type; + + unexpected_type() = delete; + + ~unexpected_type(){} + + explicit unexpected_type( std::exception_ptr const & error ) + : m_error( error ) + {} + + explicit unexpected_type(std::exception_ptr && error ) + : m_error( std::move( error ) ) + {} + + template< typename E > + explicit unexpected_type( E error ) + : m_error( std::make_exception_ptr( error ) ) + {} + + std::exception_ptr const & value() const + { + return m_error; + } + + std::exception_ptr & value() + { + return m_error; + } + +private: + std::exception_ptr m_error; +}; + +// unexpected: relational operators + +template< typename E > +constexpr bool operator==( unexpected_type<E> const & x, unexpected_type<E> const & y ) +{ + return x.value() == y.value(); +} + +template< typename E > +constexpr bool operator!=( unexpected_type<E> const & x, unexpected_type<E> const & y ) +{ + return ! ( x == y ); +} + +template< typename E > +constexpr bool operator<( unexpected_type<E> const & x, unexpected_type<E> const & y ) +{ + return x.value() < y.value(); +} + +template< typename E > +constexpr bool operator>( unexpected_type<E> const & x, unexpected_type<E> const & y ) +{ + return ( y < x ); +} + +template< typename E > +constexpr bool operator<=( unexpected_type<E> const & x, unexpected_type<E> const & y ) +{ + return ! ( y < x ); +} + +template< typename E > +constexpr bool operator>=( unexpected_type<E> const & x, unexpected_type<E> const & y ) +{ + return ! ( x < y ); +} + +inline constexpr bool operator<( unexpected_type<std::exception_ptr> const & /*x*/, unexpected_type<std::exception_ptr> const & /*y*/ ) +{ + return false; +} + +inline constexpr bool operator>( unexpected_type<std::exception_ptr> const & /*x*/, unexpected_type<std::exception_ptr> const & /*y*/ ) +{ + return false; +} + +inline constexpr bool operator<=( unexpected_type<std::exception_ptr> const & x, unexpected_type<std::exception_ptr> const & y ) +{ + return ( x == y ); +} + +inline constexpr bool operator>=( unexpected_type<std::exception_ptr> const & x, unexpected_type<std::exception_ptr> const & y ) +{ + return ( x == y ); +} + +// unexpected: traits + +template <typename E> +struct is_unexpected : std::false_type {}; + +template <typename E> +struct is_unexpected< unexpected_type<E> > : std::true_type {}; + +// unexpected: factory + +template< typename E> +nsel_constexpr14 auto +make_unexpected( E && v) -> unexpected_type< typename std::decay<E>::type > +{ + return unexpected_type< typename std::decay<E>::type >( v ); +} + +/*nsel_constexpr14*/ inline auto +make_unexpected_from_current_exception() -> unexpected_type< std::exception_ptr > +{ + return unexpected_type< std::exception_ptr >( std::current_exception() ); +} + +/// in-place tag: construct a value in-place (should come from std::experimental::optional) + +struct in_place_t{}; + +constexpr in_place_t in_place{}; + +/// unexpect tag, in_place_unexpected tag: construct an error + +struct in_place_unexpected_t{}; + +constexpr in_place_unexpected_t unexpect{}; +constexpr in_place_unexpected_t in_place_unexpected{}; + +/// expected access error + +template< typename E > +class bad_expected_access : public std::logic_error +{ +public: + typedef E error_type; + + explicit bad_expected_access( error_type error ) + : logic_error( "bad_expected_access" ) + , m_error( error ) + {} + + constexpr error_type const & error() const + { + return m_error; + } + + error_type & error() + { + return m_error; + } + +private: + error_type m_error; +}; + +/// class error_traits + +template< typename Error > +struct error_traits +{ + static void rethrow( Error const & e ) + { + throw bad_expected_access<Error>{ e }; + } +}; + +template<> +struct error_traits< std::exception_ptr > +{ + static void rethrow( std::exception_ptr const & e ) + { + std::rethrow_exception( e ); + } +}; + +template<> +struct error_traits< std::error_code > +{ + static void rethrow( std::error_code const & e ) + { + throw std::system_error( e ); + } +}; + +/// class expected + +template< typename T, typename E = std::error_code > +class expected +{ +public: + typedef T value_type; + typedef E error_type; + + // constructors + + nsel_REQUIRES_0( + std::is_default_constructible<T>::value ) + + nsel_constexpr14 expected() noexcept + ( + std::is_nothrow_default_constructible<T>::value + ) + : has_value_( true ) + { + contained.construct_value( value_type() ); + } + +// nsel_REQUIRES_0( +// std::is_copy_constructible<T>::value && +// std::is_copy_constructible<E>::value ) + + nsel_constexpr14 expected( expected const & rhs ) + : has_value_( rhs.has_value_ ) + { + if ( has_value() ) contained.construct_value( rhs.contained.value() ); + else contained.construct_error( rhs.contained.error() ); + } + +// nsel_REQUIRES_0( +// std::is_move_constructible<T>::value && +// std::is_move_constructible<E>::value ) + + nsel_constexpr14 expected( expected && rhs ) + : has_value_( rhs.has_value_ ) + { + if ( has_value() ) contained.construct_value( std::move( rhs.contained.value() ) ); + else contained.construct_error( std::move( rhs.contained.error() ) ); + } + + nsel_REQUIRES_0( + std::is_copy_constructible<T>::value ) + + nsel_constexpr14 expected( value_type const & rhs ) + : has_value_( true ) + { + contained.construct_value( rhs ); + } + + nsel_REQUIRES_0( + std::is_move_constructible<T>::value ) + + nsel_constexpr14 expected( value_type && rhs ) noexcept + ( + std::is_nothrow_move_constructible<T>::value && + std::is_nothrow_move_constructible<E>::value + ) + : has_value_( true ) + { + contained.construct_value( std::move( rhs ) ); + } + + template <typename... Args, nsel_REQUIRES_T( + std::is_constructible<T, Args&&...>::value ) > + + nsel_constexpr14 explicit expected( in_place_t, Args&&... args ) + : has_value_( true ) + { + contained.construct_value( std::forward<Args>( args )... ); + } + + template< typename U, typename... Args, nsel_REQUIRES_T( + std::is_constructible<T, std::initializer_list<U>, Args&&...>::value ) > + + nsel_constexpr14 explicit expected( in_place_t, std::initializer_list<U> il, Args&&... args ) + : has_value_( true ) + { + contained.construct_value( il, std::forward<Args>( args )... ); + } + + nsel_REQUIRES_0( + std::is_copy_constructible<E>::value ) + + nsel_constexpr14 expected( unexpected_type<E> const & error ) + : has_value_( false ) + { + contained.construct_error( error.value() ); + } + + nsel_REQUIRES_0( + std::is_move_constructible<E>::value ) + + nsel_constexpr14 expected( unexpected_type<E> && error ) + : has_value_( false ) + { + contained.construct_error( std::move( error.value() ) ); + } + + template< typename... Args, nsel_REQUIRES_T( + std::is_constructible<E, Args&&...>::value ) > + + nsel_constexpr14 explicit expected( in_place_unexpected_t, Args&&... args ) + : has_value_( false ) + { + contained.construct_error( std::forward<Args>( args )... ); + } + + template< typename U, typename... Args, nsel_REQUIRES_T( + std::is_constructible<T, std::initializer_list<U>, Args&&...>::value ) > + + nsel_constexpr14 explicit expected( in_place_unexpected_t, std::initializer_list<U> il, Args&&... args ) + : has_value_( false ) + { + contained.construct_error( il, std::forward<Args>( args )... ); + } + + // destructor + + ~expected() + { + if ( has_value() ) contained.destruct_value(); + else contained.destruct_error(); + } + + // assignment + +// nsel_REQUIRES( +// std::is_copy_constructible<T>::value && +// std::is_copy_assignable<T>::value && +// std::is_copy_constructible<E>::value && +// std::is_copy_assignable<E>::value ) + + expected operator=( expected const & rhs ) + { + expected( rhs ).swap( *this ); + return *this; + } + +// nsel_REQUIRES( +// std::is_move_constructible<T>::value && +// std::is_move_assignable<T>::value && +// std::is_move_constructible<E>::value && +// std::is_move_assignable<E>::value ) + + expected & operator=( expected && rhs ) noexcept + ( + std::is_nothrow_move_assignable<T>::value && + std::is_nothrow_move_constructible<T>::value&& + std::is_nothrow_move_assignable<E>::value && + std::is_nothrow_move_constructible<E>::value ) + { + expected( std::move( rhs ) ).swap( *this ); + return *this; + } + + template< typename U, nsel_REQUIRES_T( + std::is_constructible<T,U>::value && + std::is_assignable<T&, U>::value ) > + + expected & operator=( U && v ) + { + expected( std::forward<U>( v ) ).swap( *this ); + return *this; + } + +// nsel_REQUIRES( +// std::is_copy_constructible<E>::value && +// std::is_assignable<E&, E>::value ) + + expected & operator=( unexpected_type<E> const & u ) + { + expected( std::move( u ) ).swap( *this ); + return *this; + } + +// nsel_REQUIRES( +// std::is_copy_constructible<E>::value && +// std::is_assignable<E&, E>::value ) + + expected & operator=( unexpected_type<E> && u ) + { + expected( std::move( u ) ).swap( *this ); + return *this; + } + + template< typename... Args, nsel_REQUIRES_T( + std::is_constructible<T, Args&&...>::value ) > + + void emplace( Args &&... args ) + { + expected( in_place, std::forward<Args>(args)... ).swap( *this ); + } + + template< typename U, typename... Args, nsel_REQUIRES_T( + std::is_constructible<T, std::initializer_list<U>&, Args&&...>::value ) > + + void emplace( std::initializer_list<U> il, Args &&... args ) + { + expected( in_place, il, std::forward<Args>(args)... ).swap( *this ); + } + +// nsel_REQUIRES( +// std::is_move_constructible<T>::value && +// std::is_move_constructible<E>::value ) + + void swap( expected & rhs ) noexcept + ( + std::is_nothrow_move_constructible<T>::value && noexcept( std::swap( std::declval<T&>(), std::declval<T&>() ) ) && + std::is_nothrow_move_constructible<E>::value && noexcept( std::swap( std::declval<E&>(), std::declval<E&>() ) ) ) + { + using std::swap; + + if ( bool(*this) && bool(rhs) ) { swap( contained.value(), rhs.contained.value() ); } + else if ( ! bool(*this) && ! bool(rhs) ) { swap( contained.error(), rhs.contained.error() ); } + else if ( bool(*this) && ! bool(rhs) ) { error_type t( std::move( rhs.error() ) ); + // TBD - ?? rhs.contained.destruct_error(); + rhs.contained.construct_value( std::move( contained.value() ) ); + // TBD - ?? contained.destruct_value(); + contained.construct_error( std::move( t ) ); + swap( has_value_, rhs.has_value_ ); } + else if ( ! bool(*this) && bool(rhs) ) { rhs.swap( *this ); } + } + + // observers + + constexpr value_type const * operator ->() const + { + return assert( has_value() ), contained.value_ptr(); + } + + value_type * operator ->() + { + return assert( has_value() ), contained.value_ptr(); + } + + constexpr value_type const & operator *() const & + { + return assert( has_value() ), contained.value(); + } + + value_type & operator *() & + { + return assert( has_value() ), contained.value(); + } + + constexpr value_type && operator *() const && + { + return assert( has_value() ), std::move( contained.value() ); + } + + value_type && operator *() && + { + return assert( has_value() ), std::move( contained.value() ); + } + + + constexpr explicit operator bool() const noexcept + { + return has_value(); + } + + constexpr bool has_value() const noexcept + { + return has_value_; + } + + constexpr value_type const & value() const & + { + return has_value() + ? ( contained.value() ) + : ( error_traits<error_type>::rethrow( contained.error() ), contained.value() ); + } + + value_type & value() & + { + return has_value() + ? ( contained.value() ) + : ( error_traits<error_type>::rethrow( contained.error() ), contained.value() ); + } + + value_type && value() && + { + return has_value() + ? ( contained.value() ) + : ( error_traits<error_type>::rethrow( contained.error() ), contained.value() ); + } + + constexpr error_type const & error() const & + { + return assert( ! has_value() ), contained.error(); + } + + error_type & error() & + { + return assert( ! has_value() ), contained.error(); + } + + constexpr error_type && error() const && + { + return assert( ! has_value() ), std::move( contained.error() ); + } + + constexpr unexpected_type<E> get_unexpected() const + { + return make_unexpected( contained.error() ); + } + + template< typename Ex > + bool has_exception() const + { + return ! has_value() && std::is_base_of< Ex, decltype( get_unexpected().value() ) >::value; + } + + template< typename U, nsel_REQUIRES_T( + std::is_copy_constructible<T>::value && + std::is_convertible<U&&, T>::value ) > + + value_type value_or( U && v ) const & + { + return has_value() + ? contained.value() + : static_cast<T>( std::forward<U>( v ) ); + } + + template< typename U, nsel_REQUIRES_T( + std::is_move_constructible<T>::value && + std::is_convertible<U&&, T>::value ) > + + value_type value_or( U && v ) && + { + return has_value() + ? std::move( contained.value() ) + : static_cast<T>( std::forward<U>( v ) ); + } + + // unwrap() + +// template <class U, class E> +// constexpr expected<U,E> expected<expected<U,E>,E>::unwrap() const&; + +// template <class T, class E> +// constexpr expected<T,E> expected<T,E>::unwrap() const&; + +// template <class U, class E> +// expected<U,E> expected<expected<U,E>, E>::unwrap() &&; + +// template <class T, class E> +// template expected<T,E> expected<T,E>::unwrap() &&; + + // factories + +// template <typename Ex, typename F> +// expected<T,E> catch_exception(F&& f); + +// template <typename F> +// expected<decltype(func(declval<T>())),E> map(F&& func) ; + +// template <typename F> +// ’see below’ bind(F&& func); + +// template <typename F> +// expected<T,E> catch_error(F&& f); + +// template <typename F> +// ’see below’ then(F&& func); + +private: + bool has_value_; + expected_detail::storage_t<T,E> contained; +}; + +/// class expected, void specialization + +template< typename E > +class expected<void, E> +{ +public: + typedef void value_type; + typedef E error_type; + + template< typename U > + struct rebind + { + typedef expected<U, error_type> type; + }; + + // constructors + + constexpr expected() noexcept + : has_value_( true ) + { + } + + // nsel_REQUIRES_0( + // std::is_copy_constructible<E>::value ) + + nsel_constexpr14 expected( expected const & rhs ) + : has_value_( rhs.has_value_ ) + { + if ( ! has_value() ) contained.construct_error( rhs.contained.error() ); + } + + nsel_REQUIRES_0( + std::is_move_constructible<E>::value ) + + nsel_constexpr14 expected( expected && rhs ) noexcept + ( + true // TBD - see also non-void specialization + ) + : has_value_( rhs.has_value_ ) + { + if ( ! has_value() ) contained.construct_error( std::move( rhs.contained.error() ) ); + } + + //nsel_REQUIRES_0( + // std::is_default_constructible<E>::value ) + + constexpr explicit expected( in_place_t ) + : has_value_( true ) + { + } + +// nsel_REQUIRES( +// std::is_copy_constructible<E>::value && +// std::is_assignable<E&, E>::value ) + + nsel_constexpr14 expected( unexpected_type<E> const & error ) + : has_value_( false ) + { + contained.construct_error( error.value() ); + } + + // ?? expected( unexpected_type<E> && error ) + + template <class Err> + nsel_constexpr14 expected( unexpected_type<Err> const & error ) + : has_value_( false ) + { + contained.construct_error( error.value() ); + } + + // destructor + + ~expected() + { + if ( ! has_value() ) contained.destruct_error(); + } + + // assignment + +// nsel_REQUIRES( +// std::is_copy_constructible<E>::value && +// std::is_copy_assignable<E>::value ) + + expected & operator=(expected const & rhs ) + { + expected( rhs ).swap( *this ); + return *this; + } + +// nsel_REQUIRES( +// std::is_move_constructible<E>::value && +// std::is_move_assignable<E>::value ) + + expected & operator=( expected && rhs ) noexcept + ( + std::is_nothrow_move_assignable<E>::value && + std::is_nothrow_move_constructible<E>::value ) + { + expected( std::move( rhs ) ).swap( *this ); + return *this; + } + + void emplace() + {} + + // swap + +// nsel_REQUIRES( +// std::is_move_constructible<E>::value ) + + void swap( expected & rhs ) noexcept + ( + std::is_nothrow_move_constructible<E>::value && noexcept( std::swap( std::declval<E&>(), std::declval<E&>() ) ) + ) + { + using std::swap; + + if ( ! bool(*this) && ! bool(rhs) ) { swap( contained.error(), rhs.contained.error() ); } + else if ( bool(*this) && ! bool(rhs) ) { contained.construct_error( std::move( rhs.error() ) ); + swap( has_value_, rhs.has_value_ ); } + else if ( ! bool(*this) && bool(rhs) ) { rhs.swap( *this ); } + } + + // observers + + constexpr explicit operator bool() const noexcept + { + return has_value(); + } + + constexpr bool has_value() const noexcept + { + return has_value_; + } + + void value() const + {} + + constexpr error_type const & error() const & + { + return assert( ! has_value() ), contained.error(); + } + + error_type & error() & + { + return assert( ! has_value() ), contained.error(); + } + + constexpr error_type && error() const && + { + return assert( ! has_value() ), std::move( contained.error() ); + } + + constexpr unexpected_type<error_type> get_unexpected() const + { + return make_unexpected( contained.error() ); + } + + template <typename Ex> + bool has_exception() const + { + return ! has_value() && std::is_base_of< Ex, decltype( get_unexpected().value() ) >::value; + } + +// template constexpr ’see below’ unwrap() const&; +// +// template ’see below’ unwrap() &&; + + // factories + +// template <typename Ex, typename F> +// expected<void,E> catch_exception(F&& f); +// +// template <typename F> +// expected<decltype(func()), E> map(F&& func) ; +// +// template <typename F> +// ’see below’ bind(F&& func) ; +// +// template <typename F> +// expected<void,E> catch_error(F&& f); +// +// template <typename F> +// ’see below’ then(F&& func); + +private: + bool has_value_; + expected_detail::storage_t<void,E> contained; +}; + +// expected: relational operators + +template <typename T, typename E> +constexpr bool operator==( expected<T,E> const & x, expected<T,E> const & y ) +{ + return bool(x) != bool(y) ? false : bool(x) == false ? true : *x == *y; +} + +template <typename T, typename E> +constexpr bool operator!=( expected<T,E> const & x, expected<T,E> const & y ) +{ + return !(x == y); +} + +template <typename T, typename E> +constexpr bool operator<( expected<T,E> const & x, expected<T,E> const & y ) +{ + return (!y) ? false : (!x) ? true : *x < *y; +} + +template <typename T, typename E> +constexpr bool operator>( expected<T,E> const & x, expected<T,E> const & y ) +{ + return (y < x); +} + +template <typename T, typename E> +constexpr bool operator<=( expected<T,E> const & x, expected<T,E> const & y ) +{ + return !(y < x); +} + +template <typename T, typename E> +constexpr bool operator>=( expected<T,E> const & x, expected<T,E> const & y ) +{ + return !(x < y); +} + +// expected: comparison with unexpected_type + +template <typename T, typename E> +constexpr bool operator==( expected<T,E> const & x, unexpected_type<E> const & u ) +{ + return (!x) ? x.get_unexpected() == u : false; +} + +template <typename T, typename E> +constexpr bool operator==( unexpected_type<E> const & u, expected<T,E> const & x ) +{ + return ( x == u ); +} + +template <typename T, typename E> +constexpr bool operator!=( expected<T,E> const & x, unexpected_type<E> const & u ) +{ + return ! ( x == u ); +} + +template <typename T, typename E> +constexpr bool operator!=( unexpected_type<E> const & u, expected<T,E> const & x ) +{ + return ! ( x == u ); +} + +template <typename T, typename E> +constexpr bool operator<( expected<T,E> const & x, unexpected_type<E> const & u ) +{ + return (!x) ? ( x.get_unexpected() < u ) : false; +} + +template <typename T, typename E> +constexpr bool operator<( unexpected_type<E> const & u, expected<T,E> const & x ) +{ + return (!x) ? ( u < x.get_unexpected() ) : true ; +} + +template <typename T, typename E> +constexpr bool operator>( expected<T,E> const & x, unexpected_type<E> const & u ) +{ + return ( u < x ); +} + +template <typename T, typename E> +constexpr bool operator>( unexpected_type<E> const & u, expected<T,E> const & x ) +{ + return ( x < u ); +} + +template <typename T, typename E> +constexpr bool operator<=( expected<T,E> const & x, unexpected_type<E> const & u ) +{ + return ! ( u < x ); +} + +template <typename T, typename E> +constexpr bool operator<=( unexpected_type<E> const & u, expected<T,E> const & x) +{ + return ! ( x < u ); +} + +template <typename T, typename E> +constexpr bool operator>=( expected<T,E> const & x, unexpected_type<E> const & u ) +{ + return ! ( u > x ); +} + +template <typename T, typename E> +constexpr bool operator>=( unexpected_type<E> const & u, expected<T,E> const & x ) +{ + return ! ( x > u ); +} + +// expected: comparison with T + +template <typename T, typename E> +constexpr bool operator==( expected<T,E> const & x, T const & v ) +{ + return bool(x) ? *x == v : false; +} + +template <typename T, typename E> +constexpr bool operator==(T const & v, expected<T,E> const & x ) +{ + return bool(x) ? v == *x : false; +} + +template <typename T, typename E> +constexpr bool operator!=( expected<T,E> const & x, T const & v ) +{ + return bool(x) ? *x != v : true; +} + +template <typename T, typename E> +constexpr bool operator!=( T const & v, expected<T,E> const & x ) +{ + return bool(x) ? v != *x : true; +} + +template <typename T, typename E> +constexpr bool operator<( expected<T,E> const & x, T const & v ) +{ + return bool(x) ? *x < v : true; +} + +template <typename T, typename E> +constexpr bool operator<( T const & v, expected<T,E> const & x ) +{ + return bool(x) ? v < *x : false; +} + +template <typename T, typename E> +constexpr bool operator>( T const & v, expected<T,E> const & x ) +{ + return bool(x) ? *x < v : false; +} + +template <typename T, typename E> +constexpr bool operator>( expected<T,E> const & x, T const & v ) +{ + return bool(x) ? v < *x : false; +} + +template <typename T, typename E> +constexpr bool operator<=( T const & v, expected<T,E> const & x ) +{ + return bool(x) ? ! ( *x < v ) : false; +} + +template <typename T, typename E> +constexpr bool operator<=( expected<T,E> const & x, T const & v ) +{ + return bool(x) ? ! ( v < *x ) : true; +} + +template <typename T, typename E> +constexpr bool operator>=( expected<T,E> const & x, T const & v ) +{ + return bool(x) ? ! ( *x < v ) : false; +} + +template <typename T, typename E> +constexpr bool operator>=( T const & v, expected<T,E> const & x ) +{ + return bool(x) ? ! ( v < *x ) : true; +} + +// expected: specialized algorithms + +template< typename T, typename E > +void swap( expected<T,E> & x, expected<T,E> & y ) noexcept( noexcept( x.swap(y) ) ) +{ + x.swap( y ); +} + +template< typename T> +constexpr auto make_expected( T && v ) -> expected< typename std::decay<T>::type > +{ + return expected< typename std::decay<T>::type >( std::forward<T>( v ) ); +} + +// expected<void> specialization: + +inline auto make_expected() -> expected<void> +{ + return expected<void>( in_place ); +} + +template< typename T, typename E > +constexpr auto make_expected_from_error( E e ) -> expected<T, typename std::decay<E>::type> +{ + return expected<T, typename std::decay<E>::type>( make_unexpected( e ) ); +} + +END_OPENTRACING_ABI_NAMESPACE +} // namespace opentracing + +namespace std { + +// expected: hash support + +template< typename T, typename E > +struct hash< opentracing::expected<T,E> > +{ + typedef typename hash<T>::result_type result_type; + typedef opentracing::expected<T,E> argument_type; + + constexpr result_type operator()(argument_type const & arg) const + { + return arg ? std::hash<T>{}(*arg) : result_type{}; + } +}; + +// TBD - ?? remove? see spec. +template< typename T, typename E > +struct hash< opentracing::expected<T&,E> > +{ + typedef typename hash<T>::result_type result_type; + typedef opentracing::expected<T&,E> argument_type; + + constexpr result_type operator()(argument_type const & arg) const + { + return arg ? std::hash<T>{}(*arg) : result_type{}; + } +}; + +// TBD - implement +// bool(e), hash<expected<void,E>>()(e) shall evaluate to the hashing true; +// otherwise it evaluates to an unspecified value if E is exception_ptr or +// a combination of hashing false and hash<E>()(e.error()). + +template< typename E > +struct hash< opentracing::expected<void,E> > +{ +}; + +} // namespace std + +#undef nsel_REQUIRES +#undef nsel_REQUIRES_0 +#undef nsel_REQUIRES_T + +#endif // OPENTRACING_EXPECTED_LITE_HPP |