mirror of
https://github.com/ecency/ecency-mobile.git
synced 2024-12-02 11:15:35 +03:00
338 lines
12 KiB
C++
338 lines
12 KiB
C++
///////////////////////////////////////////////////////////////////////////////
|
|
/// \file domain.hpp
|
|
/// Contains definition of domain\<\> class template and helpers for
|
|
/// defining domains with a generator and a grammar for controlling
|
|
/// operator overloading.
|
|
//
|
|
// Copyright 2008 Eric Niebler. Distributed under the Boost
|
|
// Software License, Version 1.0. (See accompanying file
|
|
// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
|
|
|
|
#ifndef BOOST_PROTO_DOMAIN_HPP_EAN_02_13_2007
|
|
#define BOOST_PROTO_DOMAIN_HPP_EAN_02_13_2007
|
|
|
|
#include <boost/ref.hpp>
|
|
#include <boost/type_traits/is_same.hpp>
|
|
#include <boost/proto/proto_fwd.hpp>
|
|
#include <boost/proto/generate.hpp>
|
|
#include <boost/proto/detail/as_expr.hpp>
|
|
#include <boost/proto/detail/deduce_domain.hpp>
|
|
|
|
#if defined(_MSC_VER)
|
|
# pragma warning(push)
|
|
# pragma warning(disable : 4714) // function 'xxx' marked as __forceinline not inlined
|
|
#endif
|
|
|
|
namespace boost { namespace proto
|
|
{
|
|
|
|
namespace detail
|
|
{
|
|
struct not_a_generator
|
|
{};
|
|
|
|
struct not_a_grammar
|
|
{};
|
|
|
|
struct not_a_domain
|
|
{};
|
|
}
|
|
|
|
namespace domainns_
|
|
{
|
|
/// \brief For use in defining domain tags to be used
|
|
/// with \c proto::extends\<\>. A \e Domain associates
|
|
/// an expression type with a \e Generator, and optionally
|
|
/// a \e Grammar.
|
|
///
|
|
/// The Generator determines how new expressions in the
|
|
/// domain are constructed. Typically, a generator wraps
|
|
/// all new expressions in a wrapper that imparts
|
|
/// domain-specific behaviors to expressions within its
|
|
/// domain. (See \c proto::extends\<\>.)
|
|
///
|
|
/// The Grammar determines whether a given expression is
|
|
/// valid within the domain, and automatically disables
|
|
/// any operator overloads which would cause an invalid
|
|
/// expression to be created. By default, the Grammar
|
|
/// parameter defaults to the wildcard, \c proto::_, which
|
|
/// makes all expressions valid within the domain.
|
|
///
|
|
/// The Super declares the domain currently being defined
|
|
/// to be a sub-domain of Super. Expressions in sub-domains
|
|
/// can be freely combined with expressions in its super-
|
|
/// domain (and <I>its</I> super-domain, etc.).
|
|
///
|
|
/// Example:
|
|
/// \code
|
|
/// template<typename Expr>
|
|
/// struct MyExpr;
|
|
///
|
|
/// struct MyGrammar
|
|
/// : or_< terminal<_>, plus<MyGrammar, MyGrammar> >
|
|
/// {};
|
|
///
|
|
/// // Define MyDomain, in which all expressions are
|
|
/// // wrapped in MyExpr<> and only expressions that
|
|
/// // conform to MyGrammar are allowed.
|
|
/// struct MyDomain
|
|
/// : domain<generator<MyExpr>, MyGrammar>
|
|
/// {};
|
|
///
|
|
/// // Use MyDomain to define MyExpr
|
|
/// template<typename Expr>
|
|
/// struct MyExpr
|
|
/// : extends<Expr, MyExpr<Expr>, MyDomain>
|
|
/// {
|
|
/// // ...
|
|
/// };
|
|
/// \endcode
|
|
///
|
|
template<
|
|
typename Generator // = default_generator
|
|
, typename Grammar // = proto::_
|
|
, typename Super // = no_super_domain
|
|
>
|
|
struct domain
|
|
: Generator
|
|
{
|
|
typedef Generator proto_generator;
|
|
typedef Grammar proto_grammar;
|
|
typedef Super proto_super_domain;
|
|
typedef domain proto_base_domain;
|
|
|
|
/// INTERNAL ONLY
|
|
typedef void proto_is_domain_;
|
|
|
|
/// \brief A unary MonomorphicFunctionObject that turns objects into Proto
|
|
/// expression objects in this domain.
|
|
///
|
|
/// The <tt>as_expr\<\></tt> function object turns objects into Proto expressions, if
|
|
/// they are not already, by making them Proto terminals held by value if
|
|
/// possible. Objects that are already Proto expressions are left alone.
|
|
///
|
|
/// If <tt>wants_basic_expr\<Generator\>::value</tt> is true, then let \c E be \c basic_expr;
|
|
/// otherwise, let \t E be \c expr. Given an lvalue \c t of type \c T:
|
|
///
|
|
/// If \c T is not a Proto expression type the resulting terminal is
|
|
/// calculated as follows:
|
|
///
|
|
/// If \c T is a function type, an abstract type, or a type derived from
|
|
/// \c std::ios_base, let \c A be <tt>T &</tt>.
|
|
/// Otherwise, let \c A be the type \c T stripped of cv-qualifiers.
|
|
/// Then, the result of applying <tt>as_expr\<T\>()(t)</tt> is
|
|
/// <tt>Generator()(E\<tag::terminal, term\<A\> \>::make(t))</tt>.
|
|
///
|
|
/// If \c T is a Proto expression type and its generator type is different from
|
|
/// \c Generator, the result is <tt>Generator()(t)</tt>.
|
|
///
|
|
/// Otherwise, the result is \c t converted to an (un-const) rvalue.
|
|
///
|
|
template<typename T, typename IsExpr = void, typename Callable = proto::callable>
|
|
struct as_expr
|
|
: detail::as_expr<
|
|
T
|
|
, typename detail::base_generator<Generator>::type
|
|
, wants_basic_expr<Generator>::value
|
|
>
|
|
{
|
|
BOOST_PROTO_CALLABLE()
|
|
};
|
|
|
|
/// INTERNAL ONLY
|
|
///
|
|
template<typename T>
|
|
struct as_expr<T, typename T::proto_is_expr_, proto::callable>
|
|
{
|
|
BOOST_PROTO_CALLABLE()
|
|
typedef typename remove_const<T>::type result_type;
|
|
|
|
BOOST_FORCEINLINE
|
|
result_type operator()(T &e) const
|
|
{
|
|
return e;
|
|
}
|
|
};
|
|
|
|
/// \brief A unary MonomorphicFunctionObject that turns objects into Proto
|
|
/// expression objects in this domain.
|
|
///
|
|
/// The <tt>as_child\<\></tt> function object turns objects into Proto expressions, if
|
|
/// they are not already, by making them Proto terminals held by reference.
|
|
/// Objects that are already Proto expressions are simply returned by reference.
|
|
///
|
|
/// If <tt>wants_basic_expr\<Generator\>::value</tt> is true, then let \c E be \c basic_expr;
|
|
/// otherwise, let \t E be \c expr. Given an lvalue \c t of type \c T:
|
|
///
|
|
/// If \c T is not a Proto expression type the resulting terminal is
|
|
/// <tt>Generator()(E\<tag::terminal, term\<T &\> \>::make(t))</tt>.
|
|
///
|
|
/// If \c T is a Proto expression type and its generator type is different from
|
|
/// \c Generator, the result is <tt>Generator()(t)</tt>.
|
|
///
|
|
/// Otherwise, the result is the lvalue \c t.
|
|
///
|
|
template<typename T, typename IsExpr = void, typename Callable = proto::callable>
|
|
struct as_child
|
|
: detail::as_child<
|
|
T
|
|
, typename detail::base_generator<Generator>::type
|
|
, wants_basic_expr<Generator>::value
|
|
>
|
|
{
|
|
BOOST_PROTO_CALLABLE()
|
|
};
|
|
|
|
/// INTERNAL ONLY
|
|
///
|
|
template<typename T>
|
|
struct as_child<T, typename T::proto_is_expr_, proto::callable>
|
|
{
|
|
BOOST_PROTO_CALLABLE()
|
|
typedef T &result_type;
|
|
|
|
BOOST_FORCEINLINE
|
|
result_type operator()(T &e) const
|
|
{
|
|
return e;
|
|
}
|
|
};
|
|
};
|
|
|
|
/// \brief The domain expressions have by default, if
|
|
/// \c proto::extends\<\> has not been used to associate
|
|
/// a domain with an expression.
|
|
///
|
|
struct default_domain
|
|
: domain<>
|
|
{};
|
|
|
|
/// \brief A domain to use when you prefer the use of
|
|
/// \c proto::basic_expr\<\> over \c proto::expr\<\>.
|
|
///
|
|
struct basic_default_domain
|
|
: domain<basic_default_generator>
|
|
{};
|
|
|
|
/// \brief A pseudo-domain for use in functions and
|
|
/// metafunctions that require a domain parameter. It
|
|
/// indicates that the domain of the parent node should
|
|
/// be inferred from the domains of the child nodes.
|
|
///
|
|
/// \attention \c deduce_domain is not itself a valid domain.
|
|
///
|
|
struct deduce_domain
|
|
: domain<detail::not_a_generator, detail::not_a_grammar, detail::not_a_domain>
|
|
{};
|
|
|
|
/// \brief Given a domain, a tag type and an argument list,
|
|
/// compute the type of the expression to generate. This is
|
|
/// either an instance of \c proto::expr\<\> or
|
|
/// \c proto::basic_expr\<\>.
|
|
///
|
|
template<typename Domain, typename Tag, typename Args, bool WantsBasicExpr>
|
|
struct base_expr
|
|
{
|
|
typedef proto::expr<Tag, Args, Args::arity> type;
|
|
};
|
|
|
|
/// INTERNAL ONLY
|
|
///
|
|
template<typename Domain, typename Tag, typename Args>
|
|
struct base_expr<Domain, Tag, Args, true>
|
|
{
|
|
typedef proto::basic_expr<Tag, Args, Args::arity> type;
|
|
};
|
|
|
|
}
|
|
|
|
/// A metafunction that returns \c mpl::true_
|
|
/// if the type \c T is the type of a Proto domain;
|
|
/// \c mpl::false_ otherwise. If \c T inherits from
|
|
/// \c proto::domain\<\>, \c is_domain\<T\> is
|
|
/// \c mpl::true_.
|
|
template<typename T, typename Void /* = void*/>
|
|
struct is_domain
|
|
: mpl::false_
|
|
{};
|
|
|
|
/// INTERNAL ONLY
|
|
///
|
|
template<typename T>
|
|
struct is_domain<T, typename T::proto_is_domain_>
|
|
: mpl::true_
|
|
{};
|
|
|
|
/// A metafunction that returns the domain of
|
|
/// a given type. If \c T is a Proto expression
|
|
/// type, it returns that expression's associated
|
|
/// domain. If not, it returns
|
|
/// \c proto::default_domain.
|
|
template<typename T, typename Void /* = void*/>
|
|
struct domain_of
|
|
{
|
|
typedef default_domain type;
|
|
};
|
|
|
|
/// INTERNAL ONLY
|
|
///
|
|
template<typename T>
|
|
struct domain_of<T, typename T::proto_is_expr_>
|
|
{
|
|
typedef typename T::proto_domain type;
|
|
};
|
|
|
|
/// INTERNAL ONLY
|
|
///
|
|
template<typename T>
|
|
struct domain_of<T &, void>
|
|
{
|
|
typedef typename domain_of<T>::type type;
|
|
};
|
|
|
|
/// INTERNAL ONLY
|
|
///
|
|
template<typename T>
|
|
struct domain_of<boost::reference_wrapper<T>, void>
|
|
{
|
|
typedef typename domain_of<T>::type type;
|
|
};
|
|
|
|
/// INTERNAL ONLY
|
|
///
|
|
template<typename T>
|
|
struct domain_of<boost::reference_wrapper<T> const, void>
|
|
{
|
|
typedef typename domain_of<T>::type type;
|
|
};
|
|
|
|
/// A metafunction that returns \c mpl::true_
|
|
/// if the type \c SubDomain is a sub-domain of
|
|
/// \c SuperDomain; \c mpl::false_ otherwise.
|
|
template<typename SubDomain, typename SuperDomain>
|
|
struct is_sub_domain_of
|
|
: is_sub_domain_of<typename SubDomain::proto_super_domain, SuperDomain>
|
|
{};
|
|
|
|
/// INTERNAL ONLY
|
|
///
|
|
template<typename SuperDomain>
|
|
struct is_sub_domain_of<proto::no_super_domain, SuperDomain>
|
|
: mpl::false_
|
|
{};
|
|
|
|
/// INTERNAL ONLY
|
|
///
|
|
template<typename SuperDomain>
|
|
struct is_sub_domain_of<SuperDomain, SuperDomain>
|
|
: mpl::true_
|
|
{};
|
|
|
|
}}
|
|
|
|
#if defined(_MSC_VER)
|
|
# pragma warning(pop)
|
|
#endif
|
|
|
|
#endif
|