C++20 module support

CMakeLists.txt

@@ -2,18 +2,37 @@
 # 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
 
-cmake_minimum_required(VERSION 3.5...3.16)
+cmake_minimum_required(VERSION 3.5...3.31)
 
 project(boost_mp11 VERSION 1.91.0 LANGUAGES CXX)
 
-add_library(boost_mp11 INTERFACE)
+if (BOOST_USE_MODULES)
+  add_library(boost_mp11 STATIC)
+  target_sources(boost_mp11 PUBLIC FILE_SET CXX_MODULES BASE_DIRS modules FILES modules/boost_mp11.cppm)
+  set(__scope PUBLIC)
+
+  # Enable and propagate C++23, import std, and the modules macro
+  target_compile_features(boost_mp11 PUBLIC cxx_std_23)
+  set_target_properties(boost_mp11 PROPERTIES CXX_MODULE_STD 1)
+  target_compile_definitions(boost_mp11 PUBLIC BOOST_USE_MODULES)
+
+else()
+  add_library(boost_mp11 INTERFACE)
+  target_compile_features(boost_mp11 INTERFACE cxx_alias_templates cxx_variadic_templates cxx_decltype)
+  set(__scope INTERFACE)
+endif()
+
 add_library(Boost::mp11 ALIAS boost_mp11)
+target_include_directories(boost_mp11 ${__scope} include)
 
-target_include_directories(boost_mp11 INTERFACE include)
-target_compile_features(boost_mp11 INTERFACE cxx_alias_templates cxx_variadic_templates cxx_decltype)
 
 if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
 
+  # Required to call deprecated FetchContent_Populate
+  if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.30.0")
+    cmake_policy(SET CMP0169 OLD)
+  endif()
+
   # Fetch support files
 
   message(STATUS "Fetching BoostFetch.cmake")
@@ -40,10 +59,11 @@ if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
 
     set(BUILD_TESTING OFF) # hide cache variable
 
-    boost_fetch(boostorg/assert TAG develop EXCLUDE_FROM_ALL)
-    boost_fetch(boostorg/config TAG develop EXCLUDE_FROM_ALL)
-    boost_fetch(boostorg/core TAG develop EXCLUDE_FROM_ALL)
-    boost_fetch(boostorg/throw_exception TAG develop EXCLUDE_FROM_ALL)
+    # TODO: restore these tags once we start merging PRs
+    boost_fetch(anarthal/assert TAG feature/cxx20-modules EXCLUDE_FROM_ALL)
+    boost_fetch(anarthal/config TAG feature/cxx20-modules EXCLUDE_FROM_ALL)
+    boost_fetch(anarthal/core TAG feature/cxx20-modules EXCLUDE_FROM_ALL)
+    boost_fetch(anarthal/throw_exception TAG feature/cxx20-modules EXCLUDE_FROM_ALL)
 
     unset(BUILD_TESTING)
 

include/boost/mp11/bind.hpp

@@ -8,9 +8,19 @@
 //  See accompanying file LICENSE_1_0.txt or copy at
 //  http://www.boost.org/LICENSE_1_0.txt
 
+#if defined(BOOST_USE_MODULES) && !defined(BOOST_MP11_INTERFACE_UNIT)
+
+#include <boost/mp11/version.hpp>
+#ifndef BOOST_IN_MODULE_PURVIEW
+import boost.mp11;
+#endif
+
+#else
+
 #include <boost/mp11/algorithm.hpp>
 #include <boost/mp11/utility.hpp>
-#include <cstddef>
+#include <boost/mp11/detail/config.hpp>
+#include <boost/mp11/detail/std/cstddef.hpp>
 
 #if defined(_MSC_VER) || defined(__GNUC__)
 # pragma push_macro( "I" )
@@ -23,42 +33,42 @@ namespace mp11
 {
 
 // mp_bind_front
-template<template<class...> class F, class... T> struct mp_bind_front
+BOOST_MP11_EXPORT template<template<class...> class F, class... T> struct mp_bind_front
 {
     // the indirection through mp_defer works around the language inability
     // to expand U... into a fixed parameter list of an alias template
 
     template<class... U> using fn = typename mp_defer<F, T..., U...>::type;
 };
 
-template<class Q, class... T> using mp_bind_front_q = mp_bind_front<Q::template fn, T...>;
+BOOST_MP11_EXPORT template<class Q, class... T> using mp_bind_front_q = mp_bind_front<Q::template fn, T...>;
 
 // mp_bind_back
-template<template<class...> class F, class... T> struct mp_bind_back
+BOOST_MP11_EXPORT template<template<class...> class F, class... T> struct mp_bind_back
 {
     template<class... U> using fn = typename mp_defer<F, U..., T...>::type;
 };
 
-template<class Q, class... T> using mp_bind_back_q = mp_bind_back<Q::template fn, T...>;
+BOOST_MP11_EXPORT template<class Q, class... T> using mp_bind_back_q = mp_bind_back<Q::template fn, T...>;
 
 // mp_arg
-template<std::size_t I> struct mp_arg
+BOOST_MP11_EXPORT template<std::size_t I> struct mp_arg
 {
     template<class... T> using fn = mp_at_c<mp_list<T...>, I>;
 };
 
-using _1 = mp_arg<0>;
-using _2 = mp_arg<1>;
-using _3 = mp_arg<2>;
-using _4 = mp_arg<3>;
-using _5 = mp_arg<4>;
-using _6 = mp_arg<5>;
-using _7 = mp_arg<6>;
-using _8 = mp_arg<7>;
-using _9 = mp_arg<8>;
+BOOST_MP11_EXPORT using _1 = mp_arg<0>;
+BOOST_MP11_EXPORT using _2 = mp_arg<1>;
+BOOST_MP11_EXPORT using _3 = mp_arg<2>;
+BOOST_MP11_EXPORT using _4 = mp_arg<3>;
+BOOST_MP11_EXPORT using _5 = mp_arg<4>;
+BOOST_MP11_EXPORT using _6 = mp_arg<5>;
+BOOST_MP11_EXPORT using _7 = mp_arg<6>;
+BOOST_MP11_EXPORT using _8 = mp_arg<7>;
+BOOST_MP11_EXPORT using _9 = mp_arg<8>;
 
 // mp_bind
-template<template<class...> class F, class... T> struct mp_bind;
+BOOST_MP11_EXPORT template<template<class...> class F, class... T> struct mp_bind;
 
 namespace detail
 {
@@ -90,7 +100,7 @@ template<template<class...> class F, class... U, class... T> struct eval_bound_a
 
 } // namespace detail
 
-template<template<class...> class F, class... T> struct mp_bind
+BOOST_MP11_EXPORT template<template<class...> class F, class... T> struct mp_bind
 {
 #if BOOST_MP11_WORKAROUND( BOOST_MP11_MSVC, == 1915 )
 private:
@@ -108,7 +118,7 @@ template<template<class...> class F, class... T> struct mp_bind
 #endif
 };
 
-template<class Q, class... T> using mp_bind_q = mp_bind<Q::template fn, T...>;
+BOOST_MP11_EXPORT template<class Q, class... T> using mp_bind_q = mp_bind<Q::template fn, T...>;
 
 } // namespace mp11
 } // namespace boost
@@ -117,4 +127,6 @@ template<class Q, class... T> using mp_bind_q = mp_bind<Q::template fn, T...>;
 # pragma pop_macro( "I" )
 #endif
 
+#endif
+
 #endif // #ifndef BOOST_MP11_BIND_HPP_INCLUDED

include/boost/mp11/detail/config.hpp

@@ -146,4 +146,10 @@
 #  define BOOST_MP11_DEPRECATED(msg)
 #endif
 
+#if defined(BOOST_USE_MODULES)
+#  define BOOST_MP11_EXPORT export
+#else
+#  define BOOST_MP11_EXPORT
+#endif
+
 #endif // #ifndef BOOST_MP11_DETAIL_CONFIG_HPP_INCLUDED

include/boost/mp11/detail/mp_append.hpp

@@ -307,11 +307,11 @@ struct append_value_lists
 
 #if defined(BOOST_MP11_HAS_TEMPLATE_AUTO)
 
-template<class... L> using mp_append = typename mp_if_c<(sizeof...(L) > 0 && sizeof...(L) == mp_count_if<mp_list<L...>, mp_is_value_list>::value), detail::append_value_lists, detail::append_type_lists>::template fn<L...>;
+BOOST_MP11_EXPORT template<class... L> using mp_append = typename mp_if_c<(sizeof...(L) > 0 && sizeof...(L) == mp_count_if<mp_list<L...>, mp_is_value_list>::value), detail::append_value_lists, detail::append_type_lists>::template fn<L...>;
 
 #else
 
-template<class... L> using mp_append = detail::append_type_lists::fn<L...>;
+BOOST_MP11_EXPORT template<class... L> using mp_append = detail::append_type_lists::fn<L...>;
 
 #endif
 

include/boost/mp11/detail/mp_copy_if.hpp

@@ -39,8 +39,8 @@ template<template<class...> class L, class... T, template<class...> class P> str
 
 } // namespace detail
 
-template<class L, template<class...> class P> using mp_copy_if = typename detail::mp_copy_if_impl<L, P>::type;
-template<class L, class Q> using mp_copy_if_q = mp_copy_if<L, Q::template fn>;
+BOOST_MP11_EXPORT template<class L, template<class...> class P> using mp_copy_if = typename detail::mp_copy_if_impl<L, P>::type;
+BOOST_MP11_EXPORT template<class L, class Q> using mp_copy_if_q = mp_copy_if<L, Q::template fn>;
 
 } // namespace mp11
 } // namespace boost

include/boost/mp11/detail/mp_count.hpp

@@ -82,7 +82,7 @@ template<template<class...> class L, class... T, class V> struct mp_count_impl<L
 
 } // namespace detail
 
-template<class L, class V> using mp_count = typename detail::mp_count_impl<L, V>::type;
+BOOST_MP11_EXPORT template<class L, class V> using mp_count = typename detail::mp_count_impl<L, V>::type;
 
 // mp_count_if<L, P>
 namespace detail
@@ -138,8 +138,8 @@ template<template<class...> class L, class... T, template<class...> class P> str
 
 } // namespace detail
 
-template<class L, template<class...> class P> using mp_count_if = typename detail::mp_count_if_impl<L, P>::type;
-template<class L, class Q> using mp_count_if_q = mp_count_if<L, Q::template fn>;
+BOOST_MP11_EXPORT template<class L, template<class...> class P> using mp_count_if = typename detail::mp_count_if_impl<L, P>::type;
+BOOST_MP11_EXPORT template<class L, class Q> using mp_count_if_q = mp_count_if<L, Q::template fn>;
 
 } // namespace mp11
 } // namespace boost

include/boost/mp11/detail/mp_defer.hpp

@@ -33,8 +33,8 @@ template<class T, class E> struct mp_if_c_impl<false, T, E>
 
 } // namespace detail
 
-template<bool C, class T, class... E> using mp_if_c = typename detail::mp_if_c_impl<C, T, E...>::type;
-template<class C, class T, class... E> using mp_if = typename detail::mp_if_c_impl<static_cast<bool>(C::value), T, E...>::type;
+BOOST_MP11_EXPORT template<bool C, class T, class... E> using mp_if_c = typename detail::mp_if_c_impl<C, T, E...>::type;
+BOOST_MP11_EXPORT template<class C, class T, class... E> using mp_if = typename detail::mp_if_c_impl<static_cast<bool>(C::value), T, E...>::type;
 
 // mp_valid
 
@@ -55,7 +55,7 @@ struct mp_valid_impl<void_t<F<T...>>, F, T...>: mp_true {};
 
 } // namespace detail
 
-template<template<class...> class F, class... T> using mp_valid = typename detail::mp_valid_impl<void, F, T...>;
+BOOST_MP11_EXPORT template<template<class...> class F, class... T> using mp_valid = typename detail::mp_valid_impl<void, F, T...>;
 
 #else
 
@@ -73,11 +73,11 @@ template<template<class...> class F, class... T> struct mp_valid_impl
 
 } // namespace detail
 
-template<template<class...> class F, class... T> using mp_valid = typename detail::mp_valid_impl<F, T...>::type;
+BOOST_MP11_EXPORT template<template<class...> class F, class... T> using mp_valid = typename detail::mp_valid_impl<F, T...>::type;
 
 #endif
 
-template<class Q, class... T> using mp_valid_q = mp_valid<Q::template fn, T...>;
+BOOST_MP11_EXPORT template<class Q, class... T> using mp_valid_q = mp_valid<Q::template fn, T...>;
 
 // mp_defer
 namespace detail
@@ -105,11 +105,11 @@ template<template<class...> class F, class... T> struct mp_defer_cuda_workaround
 
 #if BOOST_MP11_WORKAROUND( BOOST_MP11_CUDA, >= 9000000 && BOOST_MP11_CUDA < 10000000 )
 
-template<template<class...> class F, class... T> using mp_defer = typename detail::mp_defer_cuda_workaround< F, T...>::type;
+BOOST_MP11_EXPORT template<template<class...> class F, class... T> using mp_defer = typename detail::mp_defer_cuda_workaround< F, T...>::type;
 
 #else
 
-template<template<class...> class F, class... T> using mp_defer = mp_if<mp_valid<F, T...>, detail::mp_defer_impl<F, T...>, detail::mp_no_type>;
+BOOST_MP11_EXPORT template<template<class...> class F, class... T> using mp_defer = mp_if<mp_valid<F, T...>, detail::mp_defer_impl<F, T...>, detail::mp_no_type>;
 
 #endif
 

include/boost/mp11/detail/mp_fold.hpp

@@ -157,8 +157,8 @@ struct mp_fold_impl<L<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T...>, V, F>
 
 } // namespace detail
 
-template<class L, class V, template<class...> class F> using mp_fold = typename detail::mp_fold_impl<mp_rename<L, mp_list>, V, F>::type;
-template<class L, class V, class Q> using mp_fold_q = mp_fold<L, V, Q::template fn>;
+BOOST_MP11_EXPORT template<class L, class V, template<class...> class F> using mp_fold = typename detail::mp_fold_impl<mp_rename<L, mp_list>, V, F>::type;
+BOOST_MP11_EXPORT template<class L, class V, class Q> using mp_fold_q = mp_fold<L, V, Q::template fn>;
 
 } // namespace mp11
 } // namespace boost

include/boost/mp11/detail/mp_front.hpp

@@ -42,7 +42,7 @@ template<template<auto...> class L, auto A1, auto... A> struct mp_front_impl<L<A
 
 } // namespace detail
 
-template<class L> using mp_front = typename detail::mp_front_impl<L>::type;
+BOOST_MP11_EXPORT template<class L> using mp_front = typename detail::mp_front_impl<L>::type;
 
 } // namespace mp11
 } // namespace boost

include/boost/mp11/detail/mp_is_list.hpp

@@ -9,6 +9,7 @@
 // http://www.boost.org/LICENSE_1_0.txt
 
 #include <boost/mp11/integral.hpp>
+#include <boost/mp11/detail/config.hpp>
 
 namespace boost
 {
@@ -31,7 +32,7 @@ template<template<class...> class L, class... T> struct mp_is_list_impl<L<T...>>
 
 } // namespace detail
 
-template<class L> using mp_is_list = typename detail::mp_is_list_impl<L>::type;
+BOOST_MP11_EXPORT template<class L> using mp_is_list = typename detail::mp_is_list_impl<L>::type;
 
 } // namespace mp11
 } // namespace boost

include/boost/mp11/detail/mp_is_value_list.hpp

@@ -33,7 +33,7 @@ template<template<auto...> class L, auto... A> struct mp_is_value_list_impl<L<A.
 
 } // namespace detail
 
-template<class L> using mp_is_value_list = typename detail::mp_is_value_list_impl<L>::type;
+BOOST_MP11_EXPORT template<class L> using mp_is_value_list = typename detail::mp_is_value_list_impl<L>::type;
 
 } // namespace mp11
 } // namespace boost

include/boost/mp11/detail/mp_list.hpp

@@ -8,13 +8,15 @@
 //  See accompanying file LICENSE_1_0.txt or copy at
 //  http://www.boost.org/LICENSE_1_0.txt
 
+#include <boost/mp11/detail/config.hpp>
+
 namespace boost
 {
 namespace mp11
 {
 
 // mp_list<T...>
-template<class... T> struct mp_list
+BOOST_MP11_EXPORT template<class... T> struct mp_list
 {
 };
 

include/boost/mp11/detail/mp_list_v.hpp

@@ -15,7 +15,7 @@ namespace mp11
 #if defined(BOOST_MP11_HAS_TEMPLATE_AUTO)
 
 // mp_list_v<A...>
-template<auto... A> struct mp_list_v
+BOOST_MP11_EXPORT template<auto... A> struct mp_list_v
 {
 };
 

include/boost/mp11/detail/mp_map_find.hpp

@@ -54,7 +54,7 @@ template<template<class...> class M, class... T, class K> struct mp_map_find_imp
 
 } // namespace detail
 
-template<class M, class K> using mp_map_find = typename detail::mp_map_find_impl<M, K>::type;
+BOOST_MP11_EXPORT template<class M, class K> using mp_map_find = typename detail::mp_map_find_impl<M, K>::type;
 
 #else
 
@@ -111,7 +111,7 @@ template<template<class...> class M, class... T, class K> struct mp_map_find_imp
 
 } // namespace detail
 
-template<class M, class K> using mp_map_find = typename detail::mp_map_find_impl<M, K>::type;
+BOOST_MP11_EXPORT template<class M, class K> using mp_map_find = typename detail::mp_map_find_impl<M, K>::type;
 
 #endif
 

include/boost/mp11/detail/mp_min_element.hpp

@@ -28,8 +28,8 @@ template<template<class...> class P> struct select_min
 
 } // namespace detail
 
-template<class L, template<class...> class P> using mp_min_element = mp_fold_q<mp_rest<L>, mp_first<L>, detail::select_min<P>>;
-template<class L, class Q> using mp_min_element_q = mp_min_element<L, Q::template fn>;
+BOOST_MP11_EXPORT template<class L, template<class...> class P> using mp_min_element = mp_fold_q<mp_rest<L>, mp_first<L>, detail::select_min<P>>;
+BOOST_MP11_EXPORT template<class L, class Q> using mp_min_element_q = mp_min_element<L, Q::template fn>;
 
 // mp_max_element<L, P>
 namespace detail
@@ -42,8 +42,8 @@ template<template<class...> class P> struct select_max
 
 } // namespace detail
 
-template<class L, template<class...> class P> using mp_max_element = mp_fold_q<mp_rest<L>, mp_first<L>, detail::select_max<P>>;
-template<class L, class Q> using mp_max_element_q = mp_max_element<L, Q::template fn>;
+BOOST_MP11_EXPORT template<class L, template<class...> class P> using mp_max_element = mp_fold_q<mp_rest<L>, mp_first<L>, detail::select_max<P>>;
+BOOST_MP11_EXPORT template<class L, class Q> using mp_max_element_q = mp_max_element<L, Q::template fn>;
 
 } // namespace mp11
 } // namespace boost

include/boost/mp11/detail/mp_plus.hpp

@@ -9,7 +9,7 @@
 //  http://www.boost.org/LICENSE_1_0.txt
 
 #include <boost/mp11/detail/config.hpp>
-#include <type_traits>
+#include <boost/mp11/detail/std/type_traits.hpp>
 
 namespace boost
 {
@@ -76,7 +76,7 @@ template<class T1, class T2, class T3, class T4, class T5, class T6, class T7, c
 
 } // namespace detail
 
-template<class... T> using mp_plus = typename detail::mp_plus_impl<T...>::type;
+BOOST_MP11_EXPORT template<class... T> using mp_plus = typename detail::mp_plus_impl<T...>::type;
 
 } // namespace mp11
 } // namespace boost