Document descriptor_by_pointer

.github/workflows/ci.yml

@@ -19,18 +19,15 @@ jobs:
         include:
           - toolset: gcc-4.8
             cxxstd: "03,11"
-            os: ubuntu-16.04
+            os: ubuntu-18.04
             install: g++-4.8
-          - toolset: gcc-4.9
-            cxxstd: "03,11"
-            os: ubuntu-16.04
-            install: g++-4.9
           - toolset: gcc-5
             cxxstd: "03,11,14,14-gnu,1z,1z-gnu"
-            os: ubuntu-16.04
+            os: ubuntu-18.04
+            install: g++-5
           - toolset: gcc-6
             cxxstd: "03,11,14,14-gnu,1z,1z-gnu"
-            os: ubuntu-16.04
+            os: ubuntu-18.04
             install: g++-6
           - toolset: gcc-7
             cxxstd: "03,11,14,14-gnu,17,17-gnu"
@@ -41,48 +38,29 @@ jobs:
             install: g++-8
           - toolset: gcc-9
             cxxstd: "03,11,14,17,2a"
-            os: ubuntu-18.04
+            os: ubuntu-20.04
           - toolset: gcc-10
             cxxstd: "03,11,14,17,2a"
-            os: ubuntu-18.04
+            os: ubuntu-20.04
+            install: g++-10
           - toolset: gcc-11
             cxxstd: "03,11,14,17,2a"
-            os: ubuntu-18.04
+            os: ubuntu-20.04
             install: g++-11
-          - toolset: clang
-            compiler: clang++-3.5
-            cxxstd: "03,11"
-            os: ubuntu-16.04
-            install: clang-3.5
-          - toolset: clang
-            compiler: clang++-3.6
-            cxxstd: "03,11,14"
-            os: ubuntu-16.04
-            install: clang-3.6
-          - toolset: clang
-            compiler: clang++-3.7
-            cxxstd: "03,11,14"
-            os: ubuntu-16.04
-            install: clang-3.7
-          - toolset: clang
-            compiler: clang++-3.8
-            cxxstd: "03,11,14"
-            os: ubuntu-16.04
-            install: clang-3.8
           - toolset: clang
             compiler: clang++-3.9
             cxxstd: "03,11,14"
-            os: ubuntu-16.04
+            os: ubuntu-18.04
             install: clang-3.9
           - toolset: clang
             compiler: clang++-4.0
             cxxstd: "03,11,14"
-            os: ubuntu-16.04
+            os: ubuntu-18.04
             install: clang-4.0
           - toolset: clang
             compiler: clang++-5.0
             cxxstd: "03,11,14,1z"
-            os: ubuntu-16.04
+            os: ubuntu-18.04
             install: clang-5.0
           - toolset: clang
             compiler: clang++-6.0
@@ -96,7 +74,7 @@ jobs:
             install: clang-7
           - toolset: clang
             compiler: clang++-8
-            cxxstd: "03,11,14,17,2a"
+            cxxstd: "03,11,14,17"
             os: ubuntu-20.04
             install: clang-8
           - toolset: clang
@@ -108,14 +86,17 @@ jobs:
             compiler: clang++-10
             cxxstd: "03,11,14,17,2a"
             os: ubuntu-20.04
+            install: clang-10
           - toolset: clang
             compiler: clang++-11
             cxxstd: "03,11,14,17,2a"
             os: ubuntu-20.04
+            install: clang-11
           - toolset: clang
             compiler: clang++-12
             cxxstd: "03,11,14,17,2a"
             os: ubuntu-20.04
+            install: clang-12
           - toolset: clang
             cxxstd: "03,11,14,17,2a"
             os: macos-10.15
@@ -180,6 +161,15 @@ jobs:
             addrmd: 32,64
             cxxflags: "-Zc:preprocessor"
             os: windows-2019
+          - toolset: msvc-14.3
+            cxxstd: "14,17,latest"
+            addrmd: 32,64
+            os: windows-2022
+          - toolset: msvc-14.3
+            cxxstd: "14,17,latest"
+            addrmd: 32,64
+            cxxflags: "-Zc:preprocessor"
+            os: windows-2022
           - toolset: gcc
             cxxstd: "03,11,14,17,2a"
             addrmd: 64

README.md

@@ -8,10 +8,10 @@ for more information and usage examples.
 ## Supported Compilers
 
 * GCC 5 or later with `-std=c++14` or above
-* Clang 3.6 or later with `-std=c++14` or above
+* Clang 3.9 or later with `-std=c++14` or above
 * Visual Studio 2015, 2017, 2019
 
-Tested on [Travis](https://travis-ci.org/github/pdimov/describe/) and
+Tested on [Github Actions](https://github.com/boostorg/describe/actions) and
 [Appveyor](https://ci.appveyor.com/project/pdimov/describe).
 
 ## License

doc/describe.adoc

@@ -9,6 +9,7 @@ Peter Dimov
 :toc: left
 :toclevels: 4
 :idprefix:
+:listing-caption: Code Example
 :docinfo: private-footer
 :source-highlighter: rouge
 :source-language: c++
@@ -16,6 +17,7 @@ Peter Dimov
 :leveloffset: +1
 
 include::describe/overview.adoc[]
+include::describe/changes.adoc[]
 include::describe/enums.adoc[]
 include::describe/classes.adoc[]
 include::describe/examples.adoc[]

doc/describe/changes.adoc

@@ -0,0 +1,16 @@
+////
+Copyright 2021 Peter Dimov
+Distributed under the Boost Software License, Version 1.0.
+https://www.boost.org/LICENSE_1_0.txt
+////
+
+[#changes]
+# Revision History
+:idprefix:
+
+## Changes in Boost 1.78.0
+
+* Added `has_describe_enumerators`, `has_describe_bases`, `has_describe_members`.
+* Added `enum_to_string`, `enum_from_string`.
+* Added relational and stream insertion operators.
+* Added `descriptor_by_name`, `descriptor_by_pointer`.

doc/describe/copyright.adoc

@@ -8,5 +8,5 @@ https://www.boost.org/LICENSE_1_0.txt
 # Copyright and License
 :idprefix:
 
-This documentation is copyright 2020 Peter Dimov and is distributed under
+This documentation is copyright 2020, 2021 Peter Dimov and is distributed under
 the http://www.boost.org/LICENSE_1_0.txt[Boost Software License, Version 1.0].

doc/describe/examples.adoc

@@ -35,37 +35,36 @@ include::../../example/printing_enums_rt.cpp[lines=5..-1]
 ## enum_to_string
 
 This example shows a function that, given an enumerator
-value, returns its name.
-
-Providing `enum_to_string` in a library is made difficult
-by the fact that the desired behavior when the passed value
-does not correspond to a named enumerator varies depending
-on the specific use case. But, since defining the function
-is trivial when `describe_enumerators` is available, every
-user can easily have his own.
-
-This specific example elects to return `"(unnamed)"` when
-the enum value doesn't have a name.
+value, returns its name. If the value does not correspond
+to a named value, the function returns `"(unnamed)"`.
 
 [source]
 ----
 include::../../example/enum_to_string.cpp[lines=5..-1]
 ----
 
+Since release 1.78.0, the library provides `enum_to_string`.
+It differs from the one in the example by having a second
+parameter that determines what should be returned when the
+value doesn't correspond to a named enumerator.
+
 [#example_string_to_enum]
 ## string_to_enum
 
 The opposite of the previous example; returns an enumerator
-value when given the enumerator name. The same problem exists
-here with respect to the error handling strategy when the string
-passed does not correspond to any enumerator name. This example
-throws an exception.
+value when given the enumerator name. When the string passed
+does not correspond to any enumerator name, throws an exception.
 
 [source]
 ----
 include::../../example/string_to_enum.cpp[lines=5..-1]
 ----
 
+Since release 1.78.0, the library provides `enum_from_string`.
+It differs from the function in the example by signaling failure
+by a `bool` return value instead of using exceptions. The
+enumerator value is assigned to the output argument.
+
 [#example_print_function]
 ## Defining a Universal Print Function
 
@@ -86,6 +85,27 @@ change its state and hence cannot violate its invariant.)
 include::../../example/print_function.cpp[lines=5..-1]
 ----
 
+Since release 1.78.0, this universal `operator<<` is supplied
+by the library, in the `boost::describe::operators` namespace.
+It's enabled by means of a using declaration in the namespace
+containing the described application types, like in the example
+below:
+```
+namespace app
+{
+
+struct X
+{
+    int a = 1;
+};
+
+BOOST_DESCRIBE_STRUCT(X, (), (a))
+
+using boost::describe::operators::operator<<;
+
+}
+```
+
 [#example_hash_value]
 ## Implementing hash_value
 
@@ -117,6 +137,30 @@ to all annotated classes also defined in `app`.
 include::../../example/equality.cpp[lines=5..-1]
 ----
 
+Since release 1.78.0, this universal `operator==` is supplied
+by the library, in the `boost::describe::operators` namespace.
+It's enabled by means of a using declaration in the namespace
+containing the described application types, like in the example
+below:
+```
+namespace app
+{
+
+struct X
+{
+    int a = 1;
+};
+
+BOOST_DESCRIBE_STRUCT(X, (), (a))
+
+using boost::describe::operators::operator==;
+
+}
+```
+
+The rest of the relational operators are also provided and can
+be enabled similarly.
+
 [#example_to_json]
 ## Automatic Conversion to JSON
 

doc/describe/implementation.adoc

@@ -15,11 +15,11 @@ https://boost.org/libs/mp11[Boost.Mp11].
 ## Supported Compilers
 
 * GCC 5 or later with `-std=c++14` or above
-* Clang 3.6 or later with `-std=c++14` or above
+* Clang 3.9 or later with `-std=c++14` or above
 * Visual Studio 2015, 2017, 2019
 
-Tested on https://travis-ci.org/github/pdimov/describe[Travis] and
-https://ci.appveyor.com/project/pdimov/describe[Appveyor].
+Tested on https://github.com/boostorg/describe/actions[Github Actions]
+and https://ci.appveyor.com/project/pdimov/describe[Appveyor].
 
 ## Limitations
 

doc/describe/reference.adoc

@@ -96,6 +96,8 @@ namespace describe {
 
 template<class E> using describe_enumerators = /*...*/;
 
+template<class E> using has_describe_enumerators = /*...*/;
+
 } }
 ```
 
@@ -116,6 +118,14 @@ struct Di
 ```
 where `vi` is the i-th enumerator.
 
+If `E` is not a described enumeration type, `describe_enumerators<E>` causes
+a substitution failure.
+
+### has_describe_enumerators<E>
+
+`has_describe_enumerators<E>::value` is `true` when `E` is a described
+enumeration type, `false` otherwise.
+
 ## <boost/describe/class.hpp>
 
 ```
@@ -232,6 +242,8 @@ namespace describe {
 
 template<class T, unsigned M> using describe_bases = /*...*/;
 
+template<class T> using has_describe_bases = /*...*/;
+
 } }
 ```
 
@@ -257,6 +269,18 @@ where `type` is the type of the base class, and `modifiers` are a bitwise-or
 combination of `mod_public`, `mod_protected`, `mod_private`, and `mod_virtual`
 that reflects the properties of the base class.
 
+If `T` is not a described class type, `describe_bases<T, M>` causes a
+substitution failure.
+
+### has_describe_bases<T>
+
+`has_describe_bases<T>::value` is `true` when `T` is a described class type,
+`false` otherwise.
+
+Since the library does not provide a way to describe bases and members separately,
+`has_describe_bases` and `has_describe_members` are, in practice, synonyms. They
+are provided separately for consistency.
+
 ## <boost/describe/members.hpp>
 
 ```
@@ -265,6 +289,8 @@ namespace describe {
 
 template<class T, unsigned M> using describe_members = /*...*/;
 
+template<class T> using has_describe_members = /*...*/;
+
 } }
 ```
 
@@ -294,6 +320,189 @@ member, and `modifiers` are a bitwise-or combination of `mod_public`,
 `mod_protected`, `mod_private`, `mod_static`, `mod_function`, `mod_inherited`,
 and `mod_hidden` that reflects the properties of the member.
 
+If `T` is not a described class type, `describe_members<T, M>` causes a
+substitution failure.
+
+### has_describe_members<T>
+
+`has_describe_members<T>::value` is `true` when `T` is a described class type,
+`false` otherwise.
+
+Since the library does not provide a way to describe bases and members separately,
+`has_describe_bases` and `has_describe_members` are, in practice, synonyms. They
+are provided separately for consistency.
+
+## <boost/describe/enum_to_string.hpp>
+
+```
+namespace boost {
+namespace describe {
+
+template<class E> char const * enum_to_string( E e, char const * def ) noexcept;
+
+} }
+```
+
+### enum_to_string
+
+The function `enum_to_string` returns the name of the enumerator `e`. `E` must
+be a described enumeration type. If `e` does not correspond to one of the described
+values, the function returns `def`.
+
+## <boost/describe/enum_from_string.hpp>
+
+```
+namespace boost {
+namespace describe {
+
+template<class E> bool enum_from_string( char const * name, E & e ) noexcept;
+
+} }
+```
+
+### enum_from_string
+
+The function `enum_from_string` assigns to `e` the enumerator value corresponding
+to `name` and returns `true`. `E` must be a described enumeration type. If `name`
+does not correspond to one of the described values, the function returns `false`.
+
+## <boost/describe/operators.hpp>
+
+```
+namespace boost {
+namespace describe {
+namespace operators {
+
+template<class T> bool operator==( T const& t1, T const& t2 );
+template<class T> bool operator!=( T const& t1, T const& t2 );
+template<class T> bool operator<( T const& t1, T const& t2 );
+template<class T> bool operator>( T const& t1, T const& t2 );
+template<class T> bool operator<=( T const& t1, T const& t2 );
+template<class T> bool operator>=( T const& t1, T const& t2 );
+
+template<class T, class Ch, class Tr>
+  std::basic_ostream<Ch, Tr>&
+    operator<<( std::basic_ostream<Ch, Tr>& os, T const& t );
+
+} } }
+```
+
+The header `<boost/describe/operators.hpp>` defines generic operators for
+described class types. They are used by bringing them into the namespace
+containing the described types via a using declaration, as in the example
+below:
+
+```
+namespace app
+{
+
+struct X
+{
+    int a = 1;
+};
+
+BOOST_DESCRIBE_STRUCT(X, (), (a))
+
+using boost::describe::operators::operator==;
+using boost::describe::operators::operator!=;
+using boost::describe::operators::operator<<;
+
+}
+```
+
+### operator==
+
+If all bases and members compare equal, returns `true`, otherwise `false`.
+
+### operator!=
+
+Returns the negation of `operator==`.
+
+### operator<
+
+Performs a lexicographical comparison over the bases and members in sequence
+using `operator<` and returns the result.
+
+### operator>
+
+Returns the result of `operator<` with the arguments reversed.
+
+### operator\<=
+
+Returns the negated result of `operator>`.
+
+### operator>=
+
+Returns the negated result of `operator<`.
+
+### operator<<
+
+Outputs a representation of `t` to `os` by recursively using `operator<<`
+to output all bases and then all members.
+
+## <boost/describe/descriptor_by_name.hpp>
+
+```
+namespace boost {
+namespace describe {
+
+#define BOOST_DESCRIBE_MAKE_NAME(s) /*...*/
+
+template<class L, class N> using descriptor_by_name = /*...*/;
+
+} }
+```
+
+### BOOST_DESCRIBE_MAKE_NAME
+
+The macro `BOOST_DESCRIBE_MAKE_NAME` creates a type that identifies the
+name given as an argument. It should be used as follows:
+
+```
+using N = BOOST_DESCRIBE_MAKE_NAME(some_member);
+```
+
+### descriptor_by_name
+
+`descriptor_by_name<L, N>` searches the descriptor list `L` for the member
+with the name identified by `N`. `N` should be a type created by
+`BOOST_DESCRIBE_MAKE_NAME` as in the above example. `L` is intended to be
+a list returned by `describe_members`, although since enumerator descriptors
+also have `::name`, a list returned by `describe_enumerators` will work as
+well.
+
+.Using descriptor_by_name
+```
+using L = describe_members<SomeType, mod_any_access>;
+using N = BOOST_DESCRIBE_MAKE_NAME(some_member);
+using D = descriptor_by_name<L, N>; // descriptor for SomeType::some_member
+```
+
+## <boost/describe/descriptor_by_pointer.hpp>
+
+```
+namespace boost {
+namespace describe {
+
+template<class L, auto Pm> using descriptor_by_pointer = /*...*/;
+
+} }
+```
+
+### descriptor_by_pointer
+
+`descriptor_by_pointer<L, Pm>` searches the descriptor list `L` for the member
+pointer `Pm`. `L` should be a list returned by `describe_members`.
+
+Since `auto` template parameters are a {cpp}17 feature, using
+`descriptor_by_pointer` requires {cpp}17.
+
+.Using descriptor_by_pointer
+```
+using L = describe_members<X, mod_any_access>;
+using D = descriptor_by_pointer<L, &X::a>; // descriptor for X::a
+```
+
 ## <boost/describe.hpp>
 
 This convenience header includes all the headers previously

include/boost/describe.hpp

@@ -11,5 +11,10 @@
 #include <boost/describe/enum.hpp>
 #include <boost/describe/class.hpp>
 #include <boost/describe/modifiers.hpp>
+#include <boost/describe/enum_to_string.hpp>
+#include <boost/describe/enum_from_string.hpp>
+#include <boost/describe/operators.hpp>
+#include <boost/describe/descriptor_by_name.hpp>
+#include <boost/describe/descriptor_by_pointer.hpp>
 
 #endif // #ifndef BOOST_DESCRIBE_HPP_INCLUDED

include/boost/describe/bases.hpp

@@ -1,16 +1,18 @@
 #ifndef BOOST_DESCRIBE_BASES_HPP_INCLUDED
 #define BOOST_DESCRIBE_BASES_HPP_INCLUDED
 
-// Copyright 2020 Peter Dimov
+// Copyright 2020, 2021 Peter Dimov
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt
 
 #include <boost/describe/modifiers.hpp>
+#include <boost/describe/detail/void_t.hpp>
 #include <boost/describe/detail/config.hpp>
 
 #if defined(BOOST_DESCRIBE_CXX11)
 
 #include <boost/mp11/algorithm.hpp>
+#include <type_traits>
 
 namespace boost
 {
@@ -26,10 +28,20 @@ template<unsigned M> struct base_filter
     template<class T> using fn = mp11::mp_bool< ( M & mod_any_access & T::modifiers ) != 0 >;
 };
 
+template<class T, class En = void> struct has_describe_bases: std::false_type
+{
+};
+
+template<class T> struct has_describe_bases<T, void_t<_describe_bases<T>>>: std::true_type
+{
+};
+
 } // namespace detail
 
 template<class T, unsigned M> using describe_bases = mp11::mp_copy_if_q<detail::_describe_bases<T>, detail::base_filter<M>>;
 
+template<class T> using has_describe_bases = detail::has_describe_bases<T>;
+
 } // namespace describe
 } // namespace boost
 

include/boost/describe/descriptor_by_name.hpp

@@ -0,0 +1,41 @@
+#ifndef BOOST_DESCRIBE_DESCRIPTOR_BY_NAME_HPP_INCLUDED
+#define BOOST_DESCRIBE_DESCRIPTOR_BY_NAME_HPP_INCLUDED
+
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/describe/detail/cx_streq.hpp>
+#include <boost/describe/detail/config.hpp>
+
+#if defined(BOOST_DESCRIBE_CXX14)
+
+#include <boost/mp11/algorithm.hpp>
+#include <boost/mp11/bind.hpp>
+#include <boost/mp11/integral.hpp>
+
+namespace boost
+{
+namespace describe
+{
+
+namespace detail
+{
+
+template<class D, class N> using match_by_name = mp11::mp_bool<cx_streq(N::name(), D::name)>;
+
+#define BOOST_DESCRIBE_MAKE_NAME_IMPL2(s, k) struct _boost_name_##s##_##k { static constexpr char const * name() { return #s; } }
+#define BOOST_DESCRIBE_MAKE_NAME_IMPL(s, k) BOOST_DESCRIBE_MAKE_NAME_IMPL2(s, k)
+
+} // namespace detail
+
+#define BOOST_DESCRIBE_MAKE_NAME(s) BOOST_DESCRIBE_MAKE_NAME_IMPL(s, __LINE__)
+
+template<class L, class N> using descriptor_by_name = mp11::mp_at<L, mp11::mp_find_if_q<L, mp11::mp_bind_back<detail::match_by_name, N>>>;
+
+} // namespace describe
+} // namespace boost
+
+#endif // defined(BOOST_DESCRIBE_CXX14)
+
+#endif // #ifndef BOOST_DESCRIBE_DESCRIPTOR_BY_NAME_HPP_INCLUDED

include/boost/describe/descriptor_by_pointer.hpp

@@ -0,0 +1,48 @@
+#ifndef BOOST_DESCRIBE_DESCRIPTOR_BY_POINTER_HPP_INCLUDED
+#define BOOST_DESCRIBE_DESCRIPTOR_BY_POINTER_HPP_INCLUDED
+
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/describe/detail/config.hpp>
+
+#if defined(__cpp_nontype_template_parameter_auto) && __cpp_nontype_template_parameter_auto >= 201606L
+
+#include <boost/mp11/algorithm.hpp>
+#include <boost/mp11/bind.hpp>
+#include <boost/mp11/integral.hpp>
+
+namespace boost
+{
+namespace describe
+{
+
+namespace detail
+{
+
+template<class Pm> constexpr bool cx_pmeq( Pm p1, Pm p2 )
+{
+    return p1 == p2;
+}
+
+template<class Pm1, class Pm2> constexpr bool cx_pmeq( Pm1, Pm2 )
+{
+    return false;
+}
+
+template<auto Pm> struct match_by_pointer
+{
+    template<class D> using fn = mp11::mp_bool< cx_pmeq( D::pointer, Pm ) >;
+};
+
+} // namespace detail
+
+template<class L, auto Pm> using descriptor_by_pointer = mp11::mp_at<L, mp11::mp_find_if_q<L, detail::match_by_pointer<Pm>>>;
+
+} // namespace describe
+} // namespace boost
+
+#endif // __cpp_nontype_template_parameter_auto
+
+#endif // #ifndef BOOST_DESCRIBE_DESCRIPTOR_BY_POINTER_HPP_INCLUDED

include/boost/describe/detail/cx_streq.hpp

@@ -0,0 +1,30 @@
+#ifndef BOOST_DESCRIBE_DETAIL_CX_STREQ_HPP_INCLUDED
+#define BOOST_DESCRIBE_DETAIL_CX_STREQ_HPP_INCLUDED
+
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/describe/detail/config.hpp>
+
+#if defined(BOOST_DESCRIBE_CXX11)
+
+namespace boost
+{
+namespace describe
+{
+namespace detail
+{
+
+constexpr bool cx_streq( char const * s1, char const * s2 )
+{
+    return s1[0] == s2[0] && ( s1[0] == 0 || cx_streq( s1 + 1, s2 + 1 ) );
+}
+
+} // namespace detail
+} // namespace describe
+} // namespace boost
+
+#endif // defined(BOOST_DESCRIBE_CXX11)
+
+#endif // #ifndef BOOST_DESCRIBE_DETAIL_CX_STREQ_HPP_INCLUDED

include/boost/describe/detail/void_t.hpp

@@ -0,0 +1,32 @@
+#ifndef BOOST_DESCRIBE_DETAIL_VOID_T_HPP_INCLUDED
+#define BOOST_DESCRIBE_DETAIL_VOID_T_HPP_INCLUDED
+
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/describe/detail/config.hpp>
+
+#if defined(BOOST_DESCRIBE_CXX11)
+
+namespace boost
+{
+namespace describe
+{
+namespace detail
+{
+
+template<class...> struct make_void
+{
+    using type = void;
+};
+
+template<class... T> using void_t = typename make_void<T...>::type;
+
+} // namespace detail
+} // namespace describe
+} // namespace boost
+
+#endif // defined(BOOST_DESCRIBE_CXX11)
+
+#endif // #ifndef BOOST_DESCRIBE_DETAIL_VOID_T_HPP_INCLUDED

include/boost/describe/enum_from_string.hpp

@@ -0,0 +1,44 @@
+#ifndef BOOST_DESCRIBE_ENUM_FROM_STRING_HPP_INCLUDED
+#define BOOST_DESCRIBE_ENUM_FROM_STRING_HPP_INCLUDED
+
+// Copyright 2020, 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/describe/detail/config.hpp>
+
+#if defined(BOOST_DESCRIBE_CXX14)
+
+#include <boost/describe/enumerators.hpp>
+#include <boost/mp11/algorithm.hpp>
+#include <cstring>
+
+namespace boost
+{
+namespace describe
+{
+
+template<class E, class De = describe_enumerators<E>>
+bool enum_from_string( char const* name, E& e ) noexcept
+{
+    bool found = false;
+
+    mp11::mp_for_each<De>([&](auto D){
+
+        if( !found && std::strcmp( D.name, name ) == 0 )
+        {
+            found = true;
+            e = D.value;
+        }
+
+    });
+
+    return found;
+}
+
+} // namespace describe
+} // namespace boost
+
+#endif // defined(BOOST_DESCRIBE_CXX14)
+
+#endif // #ifndef BOOST_DESCRIBE_ENUM_FROM_STRING_HPP_INCLUDED

include/boost/describe/enum_to_string.hpp

@@ -0,0 +1,39 @@
+#ifndef BOOST_DESCRIBE_ENUM_TO_STRING_HPP_INCLUDED
+#define BOOST_DESCRIBE_ENUM_TO_STRING_HPP_INCLUDED
+
+// Copyright 2020, 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/describe/detail/config.hpp>
+
+#if defined(BOOST_DESCRIBE_CXX14)
+
+#include <boost/describe/enumerators.hpp>
+#include <boost/mp11/algorithm.hpp>
+
+namespace boost
+{
+namespace describe
+{
+
+template<class E, class De = describe_enumerators<E>>
+char const * enum_to_string( E e, char const* def ) noexcept
+{
+    char const * r = def;
+
+    mp11::mp_for_each<De>([&](auto D){
+
+        if( e == D.value ) r = D.name;
+
+    });
+
+    return r;
+}
+
+} // namespace describe
+} // namespace boost
+
+#endif // defined(BOOST_DESCRIBE_CXX14)
+
+#endif // #ifndef BOOST_DESCRIBE_ENUM_TO_STRING_HPP_INCLUDED

include/boost/describe/enumerators.hpp

@@ -1,21 +1,43 @@
 #ifndef BOOST_DESCRIBE_ENUMERATORS_HPP_INCLUDED
 #define BOOST_DESCRIBE_ENUMERATORS_HPP_INCLUDED
 
-// Copyright 2020 Peter Dimov
+// Copyright 2020, 2021 Peter Dimov
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt
 
+#include <boost/describe/detail/void_t.hpp>
 #include <boost/describe/detail/config.hpp>
 
 #if defined(BOOST_DESCRIBE_CXX11)
 
+#include <type_traits>
+
 namespace boost
 {
 namespace describe
 {
 
+// describe_enumerators<E>
+
 template<class E> using describe_enumerators = decltype( boost_enum_descriptor_fn( static_cast<E*>(0) ) );
 
+// has_describe_enumerators<E>
+
+namespace detail
+{
+
+template<class E, class En = void> struct has_describe_enumerators: std::false_type
+{
+};
+
+template<class E> struct has_describe_enumerators<E, void_t<describe_enumerators<E>>>: std::true_type
+{
+};
+
+} // namespace detail
+
+template<class E> using has_describe_enumerators = detail::has_describe_enumerators<E>;
+
 } // namespace describe
 } // namespace boost
 

include/boost/describe/members.hpp

@@ -7,6 +7,9 @@
 
 #include <boost/describe/modifiers.hpp>
 #include <boost/describe/bases.hpp>
+#include <boost/describe/detail/void_t.hpp>
+#include <boost/describe/detail/cx_streq.hpp>
+#include <boost/describe/detail/config.hpp>
 
 #if defined(BOOST_DESCRIBE_CXX11)
 
@@ -15,6 +18,7 @@
 #include <boost/mp11/integral.hpp>
 #include <boost/mp11/list.hpp>
 #include <boost/mp11/bind.hpp>
+#include <type_traits>
 
 namespace boost
 {
@@ -57,11 +61,6 @@ template<template<class...> class L, class T, class V> struct describe_inherited
     using type = L<>;
 };
 
-constexpr bool cx_streq( char const * s1, char const * s2 )
-{
-    return s1[0] == s2[0] && ( s1[0] == 0 || cx_streq( s1 + 1, s2 + 1 ) );
-}
-
 template<class D1, class D2> using name_matches = mp11::mp_bool< cx_streq( D1::name, D2::name ) >;
 
 template<class D, class L> using name_is_hidden = mp11::mp_any_of_q<L, mp11::mp_bind_front<name_matches, D>>;
@@ -136,10 +135,22 @@ template<unsigned M> struct member_filter
     >;
 };
 
+// has_describe_members
+
+template<class T, class En = void> struct has_describe_members: std::false_type
+{
+};
+
+template<class T> struct has_describe_members<T, void_t<_describe_members<T>>>: std::true_type
+{
+};
+
 } // namespace detail
 
 template<class T, unsigned M> using describe_members = mp11::mp_copy_if_q<detail::describe_members<T, M>, detail::member_filter<M>>;
 
+template<class T> using has_describe_members = detail::has_describe_members<T>;
+
 } // namespace describe
 } // namespace boost
 

include/boost/describe/operators.hpp

@@ -0,0 +1,170 @@
+#ifndef BOOST_DESCRIBE_OPERATORS_HPP_INCLUDED
+#define BOOST_DESCRIBE_OPERATORS_HPP_INCLUDED
+
+// Copyright 2020, 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/describe/detail/config.hpp>
+
+#if defined(BOOST_DESCRIBE_CXX14)
+
+#include <boost/describe/bases.hpp>
+#include <boost/describe/members.hpp>
+#include <boost/describe/modifiers.hpp>
+#include <boost/mp11/algorithm.hpp>
+#include <type_traits>
+#include <iosfwd>
+
+namespace boost
+{
+namespace describe
+{
+
+namespace detail
+{
+
+template<class T,
+    class Bd = describe_bases<T, mod_any_access>,
+    class Md = describe_members<T, mod_any_access>>
+bool eq( T const& t1, T const& t2 )
+{
+    bool r = true;
+
+    mp11::mp_for_each<Bd>([&](auto D){
+
+        using B = typename decltype(D)::type;
+        r = r && (B const&)t1 == (B const&)t2;
+
+    });
+
+    mp11::mp_for_each<Md>([&](auto D){
+
+        r = r && t1.*D.pointer == t2.*D.pointer;
+
+    });
+
+    return r;
+}
+
+template<class T,
+    class Bd = describe_bases<T, mod_any_access>,
+    class Md = describe_members<T, mod_any_access>>
+bool lt( T const& t1, T const& t2 )
+{
+    int r = 0;
+
+    mp11::mp_for_each<Bd>([&](auto D){
+
+        using B = typename decltype(D)::type;
+        if( r == 0 && (B const&)t1 < (B const&)t2 ) r = -1;
+        if( r == 0 && (B const&)t2 < (B const&)t1 ) r = +1;
+
+    });
+
+    mp11::mp_for_each<Md>([&](auto D){
+
+        if( r == 0 && t1.*D.pointer < t2.*D.pointer ) r = -1;
+        if( r == 0 && t2.*D.pointer < t1.*D.pointer ) r = +1;
+
+    });
+
+    return r < 0;
+}
+
+template<class Os, class T,
+    class Bd = describe_bases<T, mod_any_access>,
+    class Md = describe_members<T, mod_any_access>>
+void print( Os& os, T const& t )
+{
+    os << "{";
+
+    bool first = true;
+
+    mp11::mp_for_each<Bd>([&](auto D){
+
+        if( !first ) { os << ", "; }
+        first = false;
+
+        using B = typename decltype(D)::type;
+        os << (B const&)t;
+
+    });
+
+    mp11::mp_for_each<Md>([&](auto D){
+
+        if( !first ) { os << ", "; }
+        first = false;
+
+        os << "." << D.name << " = " << t.*D.pointer;
+
+    });
+
+    os << "}";
+}
+
+} // namespace detail
+
+namespace operators
+{
+
+template<class T> std::enable_if_t<
+    has_describe_bases<T>::value && has_describe_members<T>::value, bool>
+    operator==( T const& t1, T const& t2 )
+{
+    return detail::eq( t1, t2 );
+}
+
+template<class T> std::enable_if_t<
+    has_describe_bases<T>::value && has_describe_members<T>::value, bool>
+    operator!=( T const& t1, T const& t2 )
+{
+    return !detail::eq( t1, t2 );
+}
+
+template<class T> std::enable_if_t<
+    has_describe_bases<T>::value && has_describe_members<T>::value, bool>
+    operator<( T const& t1, T const& t2 )
+{
+    return detail::lt( t1, t2 );
+}
+
+template<class T> std::enable_if_t<
+    has_describe_bases<T>::value && has_describe_members<T>::value, bool>
+    operator>=( T const& t1, T const& t2 )
+{
+    return !detail::lt( t1, t2 );
+}
+
+template<class T> std::enable_if_t<
+    has_describe_bases<T>::value && has_describe_members<T>::value, bool>
+    operator>( T const& t1, T const& t2 )
+{
+    return detail::lt( t2, t1 );
+}
+
+template<class T> std::enable_if_t<
+    has_describe_bases<T>::value && has_describe_members<T>::value, bool>
+    operator<=( T const& t1, T const& t2 )
+{
+    return !detail::lt( t2, t1 );
+}
+
+template<class T, class Ch, class Tr> std::enable_if_t<
+    has_describe_bases<T>::value && has_describe_members<T>::value,
+    std::basic_ostream<Ch, Tr>&>
+    operator<<( std::basic_ostream<Ch, Tr>& os, T const& t )
+{
+    os.width( 0 );
+    detail::print( os, t );
+    return os;
+}
+
+} // namespace operators
+
+} // namespace describe
+} // namespace boost
+
+#endif // defined(BOOST_DESCRIBE_CXX14)
+
+#endif // #ifndef BOOST_DESCRIBE_OPERATORS_HPP_INCLUDED

test/Jamfile

@@ -50,6 +50,21 @@ compile-fail struct_enum_fail.cpp ;
 
 run class_template_test.cpp ;
 
+run has_enumerators_test.cpp ;
+run has_bases_test.cpp ;
+run has_members_test.cpp ;
+
+run enum_to_string_test.cpp ;
+run enum_from_string_test.cpp ;
+
+run operator_eq_test.cpp ;
+run operator_lt_test.cpp ;
+
+run descriptor_by_name_test.cpp ;
+run descriptor_by_pointer_test.cpp ;
+
+# examples
+
 obj describe_cxx14 : describe_cxx14.cpp ;
 explicit describe_cxx14 ;
 

test/class_template_test.cpp

@@ -54,9 +54,9 @@ int main() {}
 BOOST_PRAGMA_MESSAGE("Skipping test because BOOST_MSVC is below 1920")
 int main() {}
 
-#elif defined(BOOST_MSVC) && BOOST_MSVC >= 1920 && BOOST_MSVC < 1930 && _MSVC_LANG <= 201703L
+#elif defined(BOOST_MSVC) && BOOST_MSVC >= 1920 && BOOST_MSVC < 1940 && _MSVC_LANG <= 201703L
 
-BOOST_PRAGMA_MESSAGE("Skipping test because BOOST_MSVC is 192x and _MSVC_LANG is 201703L or below")
+BOOST_PRAGMA_MESSAGE("Skipping test because BOOST_MSVC is 192x or 193x and _MSVC_LANG is 201703L or below")
 int main() {}
 
 #else

test/descriptor_by_name_test.cpp

@@ -0,0 +1,64 @@
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/describe/descriptor_by_name.hpp>
+#include <boost/describe/class.hpp>
+#include <boost/describe/members.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+#if !defined(BOOST_DESCRIBE_CXX14)
+
+#include <boost/config/pragma_message.hpp>
+
+BOOST_PRAGMA_MESSAGE("Skipping test because C++14 is not available")
+int main() {}
+
+#else
+
+struct X
+{
+    int a = 1;
+    int b = 2;
+};
+
+BOOST_DESCRIBE_STRUCT(X, (), (a, b))
+
+struct Y
+{
+    int a = 1;
+    int c = 3;
+};
+
+BOOST_DESCRIBE_STRUCT(Y, (), (a, c))
+
+int main()
+{
+    {
+        using L = boost::describe::describe_members<X, boost::describe::mod_any_access>;
+
+        using Na = BOOST_DESCRIBE_MAKE_NAME( a );
+        using Da = boost::describe::descriptor_by_name<L, Na>;
+        BOOST_TEST_CSTR_EQ( Da::name, "a" );
+
+        using Nb = BOOST_DESCRIBE_MAKE_NAME( b );
+        using Db = boost::describe::descriptor_by_name<L, Nb>;
+        BOOST_TEST_CSTR_EQ( Db::name, "b" );
+    }
+
+    {
+        using L = boost::describe::describe_members<Y, boost::describe::mod_any_access>;
+
+        using Na = BOOST_DESCRIBE_MAKE_NAME( a );
+        using Da = boost::describe::descriptor_by_name<L, Na>;
+        BOOST_TEST_CSTR_EQ( Da::name, "a" );
+
+        using Nc = BOOST_DESCRIBE_MAKE_NAME( c );
+        using Dc = boost::describe::descriptor_by_name<L, Nc>;
+        BOOST_TEST_CSTR_EQ( Dc::name, "c" );
+    }
+
+    return boost::report_errors();
+}
+
+#endif // !defined(BOOST_DESCRIBE_CXX14)

test/descriptor_by_pointer_test.cpp

@@ -0,0 +1,65 @@
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/describe/descriptor_by_pointer.hpp>
+#include <boost/describe/class.hpp>
+#include <boost/describe/members.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+#if !defined(__cpp_nontype_template_parameter_auto) || __cpp_nontype_template_parameter_auto < 201606L
+
+#include <boost/config/pragma_message.hpp>
+
+BOOST_PRAGMA_MESSAGE("Skipping test because __cpp_nontype_template_parameter_auto is not defined")
+int main() {}
+
+#else
+
+struct X
+{
+    int a = 1;
+    float b = 3.14f;
+};
+
+BOOST_DESCRIBE_STRUCT(X, (), (a, b))
+
+struct Y: public X
+{
+    long a = 2;
+    double c = 3.14;
+};
+
+BOOST_DESCRIBE_STRUCT(Y, (X), (a, c))
+
+int main()
+{
+    using namespace boost::describe;
+
+    {
+        using L = describe_members<X, mod_any_access>;
+
+        using Da = descriptor_by_pointer<L, &X::a>;
+        BOOST_TEST_CSTR_EQ( Da::name, "a" );
+
+        using Db = descriptor_by_pointer<L, &X::b>;
+        BOOST_TEST_CSTR_EQ( Db::name, "b" );
+    }
+
+    {
+        using L = describe_members<Y, mod_any_access | mod_inherited>;
+
+        using Da = descriptor_by_pointer<L, &Y::a>;
+        BOOST_TEST_CSTR_EQ( Da::name, "a" );
+
+        using Db = descriptor_by_pointer<L, &Y::b>;
+        BOOST_TEST_CSTR_EQ( Db::name, "b" );
+
+        using Dc = descriptor_by_pointer<L, &Y::c>;
+        BOOST_TEST_CSTR_EQ( Dc::name, "c" );
+    }
+
+    return boost::report_errors();
+}
+
+#endif // __cpp_nontype_template_parameter_auto

test/enum_from_string_test.cpp

@@ -0,0 +1,62 @@
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/describe/enum_from_string.hpp>
+#include <boost/describe/enum.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+#if !defined(BOOST_DESCRIBE_CXX14)
+
+#include <boost/config/pragma_message.hpp>
+
+BOOST_PRAGMA_MESSAGE("Skipping test because C++14 is not available")
+int main() {}
+
+#else
+
+enum E1 { v101 = 101, v102 = 102 };
+BOOST_DESCRIBE_ENUM(E1, v101, v102)
+
+enum class E2 { v201 = 201, v202 = 202 };
+BOOST_DESCRIBE_ENUM(E2, v201, v202)
+
+BOOST_DEFINE_ENUM(E3, v301, v302);
+BOOST_DEFINE_ENUM_CLASS(E4, v401, v402)
+
+int main()
+{
+    using boost::describe::enum_from_string;
+
+    {
+        E1 w{};
+        BOOST_TEST( enum_from_string( "v101", w ) ) && BOOST_TEST_EQ( w, v101 );
+        BOOST_TEST( enum_from_string( "v102", w ) ) && BOOST_TEST_EQ( w, v102 );
+        BOOST_TEST_NOT( enum_from_string( "v103", w ) );
+    }
+
+    {
+        E2 w{};
+        BOOST_TEST( enum_from_string( "v201", w ) ) && BOOST_TEST_EQ( (int)w, (int)E2::v201 );
+        BOOST_TEST( enum_from_string( "v202", w ) ) && BOOST_TEST_EQ( (int)w, (int)E2::v202 );
+        BOOST_TEST_NOT( enum_from_string( "v203", w ) );
+    }
+
+    {
+        E3 w{};
+        BOOST_TEST( enum_from_string( "v301", w ) ) && BOOST_TEST_EQ( w, v301 );
+        BOOST_TEST( enum_from_string( "v302", w ) ) && BOOST_TEST_EQ( w, v302 );
+        BOOST_TEST_NOT( enum_from_string( "v303", w ) );
+    }
+
+    {
+        E4 w{};
+        BOOST_TEST( enum_from_string( "v401", w ) ) && BOOST_TEST_EQ( (int)w, (int)E4::v401 );
+        BOOST_TEST( enum_from_string( "v402", w ) ) && BOOST_TEST_EQ( (int)w, (int)E4::v402 );
+        BOOST_TEST_NOT( enum_from_string( "v403", w ) );
+    }
+
+    return boost::report_errors();
+}
+
+#endif // !defined(BOOST_DESCRIBE_CXX14)

test/enum_to_string_test.cpp

@@ -0,0 +1,41 @@
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/describe/enum_to_string.hpp>
+#include <boost/describe/enum.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+#if !defined(BOOST_DESCRIBE_CXX14)
+
+#include <boost/config/pragma_message.hpp>
+
+BOOST_PRAGMA_MESSAGE("Skipping test because C++14 is not available")
+int main() {}
+
+#else
+
+enum E1 { v1 };
+BOOST_DESCRIBE_ENUM(E1, v1)
+
+enum class E2 { v2 };
+BOOST_DESCRIBE_ENUM(E2, v2)
+
+BOOST_DEFINE_ENUM(E3, v3);
+BOOST_DEFINE_ENUM_CLASS(E4, v4)
+
+int main()
+{
+    using boost::describe::enum_to_string;
+
+    BOOST_TEST_CSTR_EQ( enum_to_string( v1, "" ), "v1" );
+    BOOST_TEST_CSTR_EQ( enum_to_string( E2::v2, "" ), "v2" );
+    BOOST_TEST_CSTR_EQ( enum_to_string( static_cast<E2>( 14 ), "__def__" ), "__def__" );
+    BOOST_TEST_CSTR_EQ( enum_to_string( v3, "" ), "v3" );
+    BOOST_TEST_CSTR_EQ( enum_to_string( E4::v4, "" ), "v4" );
+    BOOST_TEST_EQ( enum_to_string( static_cast<E4>( 14 ), 0 ), static_cast<char const*>( 0 ) );
+
+    return boost::report_errors();
+}
+
+#endif // !defined(BOOST_DESCRIBE_CXX14)

test/has_bases_test.cpp

@@ -0,0 +1,55 @@
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/describe/bases.hpp>
+#include <boost/describe/class.hpp>
+#include <boost/core/lightweight_test_trait.hpp>
+
+#if !defined(BOOST_DESCRIBE_CXX11)
+
+#include <boost/config/pragma_message.hpp>
+
+BOOST_PRAGMA_MESSAGE("Skipping test because C++11 is not available")
+int main() {}
+
+#else
+
+struct X1 {};
+BOOST_DESCRIBE_STRUCT(X1, (), ())
+
+class X2
+{
+    BOOST_DESCRIBE_CLASS(X2, (), (), (), ())
+};
+
+struct X3 {};
+class X4 {};
+union X5 {};
+
+int main()
+{
+    using boost::describe::has_describe_bases;
+
+#if defined(BOOST_DESCRIBE_CXX14)
+
+    BOOST_TEST_TRAIT_TRUE((has_describe_bases<X1>));
+    BOOST_TEST_TRAIT_TRUE((has_describe_bases<X2>));
+
+#else
+
+    BOOST_TEST_TRAIT_FALSE((has_describe_bases<X1>));
+    BOOST_TEST_TRAIT_FALSE((has_describe_bases<X2>));
+
+#endif
+
+    BOOST_TEST_TRAIT_FALSE((has_describe_bases<X3>));
+    BOOST_TEST_TRAIT_FALSE((has_describe_bases<X4>));
+    BOOST_TEST_TRAIT_FALSE((has_describe_bases<X5>));
+    BOOST_TEST_TRAIT_FALSE((has_describe_bases<int>));
+    BOOST_TEST_TRAIT_FALSE((has_describe_bases<void>));
+
+    return boost::report_errors();
+}
+
+#endif // !defined(BOOST_DESCRIBE_CXX11)

test/has_enumerators_test.cpp

@@ -0,0 +1,58 @@
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/describe/enumerators.hpp>
+#include <boost/describe/enum.hpp>
+#include <boost/core/lightweight_test_trait.hpp>
+
+#if !defined(BOOST_DESCRIBE_CXX11)
+
+#include <boost/config/pragma_message.hpp>
+
+BOOST_PRAGMA_MESSAGE("Skipping test because C++11 is not available")
+int main() {}
+
+#else
+
+enum E1 { v1 };
+BOOST_DESCRIBE_ENUM(E1, v1)
+
+enum class E2 { v2 };
+BOOST_DESCRIBE_ENUM(E2, v2)
+
+BOOST_DEFINE_ENUM(E3, v3);
+BOOST_DEFINE_ENUM_CLASS(E4, v4)
+
+enum E5 { v5 };
+enum class E6 { v6 };
+
+int main()
+{
+    using boost::describe::has_describe_enumerators;
+
+#if defined(BOOST_DESCRIBE_CXX14)
+
+    BOOST_TEST_TRAIT_TRUE((has_describe_enumerators<E1>));
+    BOOST_TEST_TRAIT_TRUE((has_describe_enumerators<E2>));
+    BOOST_TEST_TRAIT_TRUE((has_describe_enumerators<E3>));
+    BOOST_TEST_TRAIT_TRUE((has_describe_enumerators<E4>));
+
+#else
+
+    BOOST_TEST_TRAIT_FALSE((has_describe_enumerators<E1>));
+    BOOST_TEST_TRAIT_FALSE((has_describe_enumerators<E2>));
+    BOOST_TEST_TRAIT_FALSE((has_describe_enumerators<E3>));
+    BOOST_TEST_TRAIT_FALSE((has_describe_enumerators<E4>));
+
+#endif
+
+    BOOST_TEST_TRAIT_FALSE((has_describe_enumerators<E5>));
+    BOOST_TEST_TRAIT_FALSE((has_describe_enumerators<E6>));
+    BOOST_TEST_TRAIT_FALSE((has_describe_enumerators<int>));
+    BOOST_TEST_TRAIT_FALSE((has_describe_enumerators<void>));
+
+    return boost::report_errors();
+}
+
+#endif // !defined(BOOST_DESCRIBE_CXX11)

test/has_members_test.cpp

@@ -0,0 +1,55 @@
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/describe/members.hpp>
+#include <boost/describe/class.hpp>
+#include <boost/core/lightweight_test_trait.hpp>
+
+#if !defined(BOOST_DESCRIBE_CXX11)
+
+#include <boost/config/pragma_message.hpp>
+
+BOOST_PRAGMA_MESSAGE("Skipping test because C++11 is not available")
+int main() {}
+
+#else
+
+struct X1 {};
+BOOST_DESCRIBE_STRUCT(X1, (), ())
+
+class X2
+{
+    BOOST_DESCRIBE_CLASS(X2, (), (), (), ())
+};
+
+struct X3 {};
+class X4 {};
+union X5 {};
+
+int main()
+{
+    using boost::describe::has_describe_members;
+
+#if defined(BOOST_DESCRIBE_CXX14)
+
+    BOOST_TEST_TRAIT_TRUE((has_describe_members<X1>));
+    BOOST_TEST_TRAIT_TRUE((has_describe_members<X2>));
+
+#else
+
+    BOOST_TEST_TRAIT_FALSE((has_describe_members<X1>));
+    BOOST_TEST_TRAIT_FALSE((has_describe_members<X2>));
+
+#endif
+
+    BOOST_TEST_TRAIT_FALSE((has_describe_members<X3>));
+    BOOST_TEST_TRAIT_FALSE((has_describe_members<X4>));
+    BOOST_TEST_TRAIT_FALSE((has_describe_members<X5>));
+    BOOST_TEST_TRAIT_FALSE((has_describe_members<int>));
+    BOOST_TEST_TRAIT_FALSE((has_describe_members<void>));
+
+    return boost::report_errors();
+}
+
+#endif // !defined(BOOST_DESCRIBE_CXX11)

test/members_test7.cpp

@@ -59,7 +59,7 @@ int main()
 
         using D1 = mp_at_c<L, 0>;
 
-#if !BOOST_WORKAROUND(BOOST_MSVC, < 1930)
+#if !BOOST_WORKAROUND(BOOST_MSVC, < 1940)
 // https://developercommunity.visualstudio.com/content/problem/1186002/constexpr-pointer-to-member-has-incorrect-value.html
         BOOST_TEST( D1::pointer == &C::m2 );
 #endif
@@ -79,7 +79,7 @@ int main()
         BOOST_TEST_CSTR_EQ( D1::name, "m1" );
         BOOST_TEST_EQ( D1::modifiers, mod_public | mod_inherited );
 
-#if !BOOST_WORKAROUND(BOOST_MSVC, < 1930)
+#if !BOOST_WORKAROUND(BOOST_MSVC, < 1940)
         BOOST_TEST( D2::pointer == &C::m2 );
 #endif
         BOOST_TEST_CSTR_EQ( D2::name, "m2" );

test/operator_eq_test.cpp

@@ -0,0 +1,91 @@
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/describe/operators.hpp>
+#include <boost/describe/class.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+#if !defined(BOOST_DESCRIBE_CXX14)
+
+#include <boost/config/pragma_message.hpp>
+
+BOOST_PRAGMA_MESSAGE("Skipping test because C++14 is not available")
+int main() {}
+
+#else
+
+namespace app
+{
+
+struct X
+{
+};
+
+BOOST_DESCRIBE_STRUCT(X, (), ())
+
+using boost::describe::operators::operator==;
+using boost::describe::operators::operator<<;
+
+struct Y
+{
+    int a = 1;
+};
+
+BOOST_DESCRIBE_STRUCT(Y, (), (a))
+
+using boost::describe::operators::operator==;
+using boost::describe::operators::operator!=;
+using boost::describe::operators::operator<<;
+
+struct Z: X, Y
+{
+    int b = 4;
+};
+
+BOOST_DESCRIBE_STRUCT(Z, (X, Y), (b))
+
+using boost::describe::operators::operator==;
+using boost::describe::operators::operator!=;
+using boost::describe::operators::operator<<;
+
+} // namespace app
+
+int main()
+{
+    using app::X;
+
+    {
+        X x1, x2;
+        BOOST_TEST_EQ( x1, x2 );
+    }
+
+    using app::Y;
+
+    {
+        Y y1, y2, y3;
+
+        y3.a = 2;
+
+        BOOST_TEST_EQ( y1, y2 );
+        BOOST_TEST_NE( y1, y3 );
+    }
+
+    using app::Z;
+
+    {
+        Z z1, z2, z3, z4;
+
+        z3.a = 2;
+        z4.b = 3;
+
+        BOOST_TEST_EQ( z1, z2 );
+        BOOST_TEST_NE( z1, z3 );
+        BOOST_TEST_NE( z1, z4 );
+        BOOST_TEST_NE( z3, z4 );
+    }
+
+    return boost::report_errors();
+}
+
+#endif // !defined(BOOST_DESCRIBE_CXX14)

test/operator_lt_test.cpp

@@ -0,0 +1,99 @@
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/describe/operators.hpp>
+#include <boost/describe/class.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+#if !defined(BOOST_DESCRIBE_CXX14)
+
+#include <boost/config/pragma_message.hpp>
+
+BOOST_PRAGMA_MESSAGE("Skipping test because C++14 is not available")
+int main() {}
+
+#else
+
+namespace app
+{
+
+struct X
+{
+};
+
+BOOST_DESCRIBE_STRUCT(X, (), ())
+
+using boost::describe::operators::operator<=;
+using boost::describe::operators::operator>=;
+using boost::describe::operators::operator<<;
+
+struct Y
+{
+    int a = 1;
+};
+
+BOOST_DESCRIBE_STRUCT(Y, (), (a))
+
+using boost::describe::operators::operator<;
+using boost::describe::operators::operator>;
+using boost::describe::operators::operator<=;
+using boost::describe::operators::operator>=;
+using boost::describe::operators::operator<<;
+
+struct Z: X, Y
+{
+    int b = 4;
+};
+
+BOOST_DESCRIBE_STRUCT(Z, (X, Y), (b))
+
+using boost::describe::operators::operator<;
+using boost::describe::operators::operator>;
+using boost::describe::operators::operator<=;
+using boost::describe::operators::operator>=;
+using boost::describe::operators::operator<<;
+
+} // namespace app
+
+#define TEST_EQ(x, y) BOOST_TEST_LE(x, y); BOOST_TEST_GE(x, y); BOOST_TEST_NOT((x) < (y)); BOOST_TEST_NOT((x) > (y))
+#define TEST_LT(x, y) BOOST_TEST_LT(x, y); BOOST_TEST_LE(x, y); BOOST_TEST_GT(y, x); BOOST_TEST_GE(y, x)
+
+int main()
+{
+    using app::X;
+
+    {
+        X x1, x2;
+        TEST_EQ( x1, x2 );
+    }
+
+    using app::Y;
+
+    {
+        Y y1, y2, y3;
+
+        y3.a = 2;
+
+        TEST_EQ( y1, y2 );
+        TEST_LT( y1, y3 );
+    }
+
+    using app::Z;
+
+    {
+        Z z1, z2, z3, z4;
+
+        z3.a = 2;
+        z4.b = 3;
+
+        TEST_EQ( z1, z2 );
+        TEST_LT( z1, z3 );
+        TEST_LT( z4, z1 );
+        TEST_LT( z4, z3 );
+    }
+
+    return boost::report_errors();
+}
+
+#endif // !defined(BOOST_DESCRIBE_CXX14)