From ced4870cb0d3ba183e4b17edf94bbb60c8a73629 Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@pdimov.com>
Date: Sat, 15 Jul 2017 23:03:38 +0300
Subject: [PATCH 1/4] Add is_list_constructible

---
 doc/is_list_constructible.qbk                 | 23 +++++
 doc/type_traits.qbk                           |  2 +
 doc/value_traits.qbk                          |  3 +
 include/boost/type_traits.hpp                 |  1 +
 .../type_traits/is_list_constructible.hpp     | 41 ++++++++
 test/is_list_constructible_test.cpp           | 95 +++++++++++++++++++
 6 files changed, 165 insertions(+)
 create mode 100644 doc/is_list_constructible.qbk
 create mode 100644 include/boost/type_traits/is_list_constructible.hpp
 create mode 100644 test/is_list_constructible_test.cpp

diff --git a/doc/is_list_constructible.qbk b/doc/is_list_constructible.qbk
new file mode 100644
index 0000000..733d2e8
--- /dev/null
+++ b/doc/is_list_constructible.qbk
@@ -0,0 +1,23 @@
+[/ 
+  Copyright 2017 Peter Dimov
+
+  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).
+]
+
+[section:is_list_constructible is_list_constructible]
+
+   template <class T, class... Args>
+   struct is_list_constructible : public __tof {};
+    
+__inherit If `T` can be constructed from `Args` using list initialization
+(`T{declval<Args>()...}`), then inherits from __true_type, otherwise inherits from
+__false_type. `T` must be a complete type.
+
+__compat This trait requires C++11.
+
+__header ` #include <boost/type_traits/is_list_constructible.hpp>` or ` #include <boost/type_traits.hpp>`
+
+[endsect]
diff --git a/doc/type_traits.qbk b/doc/type_traits.qbk
index 1a1fa5b..0c917e1 100644
--- a/doc/type_traits.qbk
+++ b/doc/type_traits.qbk
@@ -72,6 +72,7 @@
 [def __is_copy_constructible [link boost_typetraits.reference.is_copy_constructible is_copy_constructible]]
 [def __is_copy_assignable [link boost_typetraits.reference.is_copy_assignable is_copy_assignable]]
 [def __is_constructible [link boost_typetraits.reference.is_constructible is_constructible]]
+[def __is_list_constructible [link boost_typetraits.reference.is_list_constructible is_list_constructible]]
 [def __is_default_constructible [link boost_typetraits.reference.is_default_constructible is_default_constructible]]
 [def __is_destructible [link boost_typetraits.reference.is_destructible is_destructible]]
 [def __is_volatile [link boost_typetraits.reference.is_volatile is_volatile]]
@@ -294,6 +295,7 @@ See __has_trivial_constructor.
 [include is_function.qbk]
 [include is_fundamental.qbk]
 [include is_integral.qbk]
+[include is_list_constructible.qbk]
 [include is_lvalue_reference.qbk]
 [include is_member_function_pointer.qbk]
 [include is_member_object_pointer.qbk]
diff --git a/doc/value_traits.qbk b/doc/value_traits.qbk
index 5f667aa..f8ff399 100644
--- a/doc/value_traits.qbk
+++ b/doc/value_traits.qbk
@@ -168,6 +168,9 @@ The following templates describe the general properties of a type.
    template <class T>
    struct __is_default_constructible;
 
+   template <class T, class... Args>
+   struct __is_list_constructible;
+
    template <class T>
    struct __is_destructible;
 
diff --git a/include/boost/type_traits.hpp b/include/boost/type_traits.hpp
index dbc8c95..e5810b4 100644
--- a/include/boost/type_traits.hpp
+++ b/include/boost/type_traits.hpp
@@ -107,6 +107,7 @@
 #include <boost/type_traits/is_function.hpp>
 #include <boost/type_traits/is_fundamental.hpp>
 #include <boost/type_traits/is_integral.hpp>
+#include <boost/type_traits/is_list_constructible.hpp>
 #include <boost/type_traits/is_lvalue_reference.hpp>
 #include <boost/type_traits/is_member_function_pointer.hpp>
 #include <boost/type_traits/is_member_object_pointer.hpp>
diff --git a/include/boost/type_traits/is_list_constructible.hpp b/include/boost/type_traits/is_list_constructible.hpp
new file mode 100644
index 0000000..518a75b
--- /dev/null
+++ b/include/boost/type_traits/is_list_constructible.hpp
@@ -0,0 +1,41 @@
+#ifndef BOOST_TYPE_TRAITS_IS_LIST_CONSTRUCTIBLE_HPP_INCLUDED
+#define BOOST_TYPE_TRAITS_IS_LIST_CONSTRUCTIBLE_HPP_INCLUDED
+
+//  Copyright 2017 Peter Dimov
+//
+//  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
+
+#include <boost/config.hpp>
+#include <boost/type_traits/integral_constant.hpp>
+#include <boost/type_traits/declval.hpp>
+
+namespace boost
+{
+
+#if defined(BOOST_NO_SFINAE_EXPR) || defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) || defined(BOOST_NO_CXX11_DECLTYPE) || defined(BOOST_NO_CXX11_UNIFIED_INITIALIZATION_SYNTAX) || defined(BOOST_NO_CXX11_FUNCTION_TEMPLATE_DEFAULT_ARGS)
+
+template<class T, class = void, class = void, class = void, class = void, class = void, class = void> struct is_list_constructible: false_type
+{
+};
+
+#else
+
+namespace type_traits_detail
+{
+
+template<class T, class... A, class = decltype( T{declval<A>()...} )> true_type is_list_constructible_impl( int );
+template<class T, class... A> false_type is_list_constructible_impl( ... );
+
+} // namespace type_traits_detail
+
+template<class T, class... A> struct is_list_constructible: decltype( type_traits_detail::is_list_constructible_impl<T, A...>(0) )
+{
+};
+
+#endif
+
+} // namespace boost
+
+#endif // #ifndef BOOST_TYPE_TRAITS_IS_LIST_CONSTRUCTIBLE_HPP_INCLUDED
diff --git a/test/is_list_constructible_test.cpp b/test/is_list_constructible_test.cpp
new file mode 100644
index 0000000..d659196
--- /dev/null
+++ b/test/is_list_constructible_test.cpp
@@ -0,0 +1,95 @@
+
+//  Copyright 2017 Peter Dimov
+//
+//  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
+
+#if defined( __GNUC__ ) && (__GNUC__ >= 7)
+#pragma GCC diagnostic ignored "-Wnarrowing"
+#endif
+
+#ifdef TEST_STD
+#  include <type_traits>
+#else
+#  include <boost/type_traits/is_list_constructible.hpp>
+#endif
+#include "test.hpp"
+#include "check_integral_constant.hpp"
+
+#if defined(BOOST_NO_SFINAE_EXPR) || defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) || defined(BOOST_NO_CXX11_DECLTYPE) \
+    || defined(BOOST_NO_CXX11_UNIFIED_INITIALIZATION_SYNTAX) || defined(BOOST_NO_CXX11_FUNCTION_TEMPLATE_DEFAULT_ARGS)
+
+int main() {}
+
+#else
+
+#include <vector>
+
+struct X
+{
+    int a;
+    int b;
+};
+
+struct Y
+{
+    Y( int = 0, int = 0 );
+};
+
+struct Z
+{
+    explicit Z( int = 0, int = 0 );
+};
+
+struct V
+{
+    V( int&, int& );
+};
+
+TT_TEST_BEGIN(is_list_constructible)
+
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<int>::value), true);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<int, int>::value), true);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<int, int const>::value), true);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<int, int, int>::value), false);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<int, char>::value), true);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<int, float>::value), false);
+
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<X>::value), true);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<X, int>::value), true);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<X, int const>::value), true);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<X, int, int>::value), true);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<X, int const, int const>::value), true);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<X, int, int, int>::value), false);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<X, float>::value), false);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<X, int, float>::value), false);
+
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Y>::value), true);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Y, int>::value), true);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Y, int const>::value), true);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Y, int, int>::value), true);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Y, int const, int const>::value), true);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Y, int, int, int>::value), false);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Y, float>::value), false);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Y, int, float>::value), false);
+
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Z>::value), true);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Z, int>::value), true);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Z, int const>::value), true);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Z, int, int>::value), true);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Z, int const, int const>::value), true);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Z, int, int, int>::value), false);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Z, float>::value), false);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Z, int, float>::value), false);
+
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<V>::value), false);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<V, int>::value), false);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<V, int, int>::value), false);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<V, int, int, int>::value), false);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<V, int&, int&>::value), true);
+BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<V, int const&, int const&>::value), false);
+
+TT_TEST_END
+
+#endif

From d5be3746a1eb202663cb8264ab2d4769f6fe9d12 Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@pdimov.com>
Date: Sun, 16 Jul 2017 01:20:50 +0300
Subject: [PATCH 2/4] Suppress warnings on g++ 4.x

---
 test/is_list_constructible_test.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/test/is_list_constructible_test.cpp b/test/is_list_constructible_test.cpp
index d659196..2e7ee62 100644
--- a/test/is_list_constructible_test.cpp
+++ b/test/is_list_constructible_test.cpp
@@ -5,8 +5,9 @@
 //  See accompanying file LICENSE_1_0.txt or copy at
 //  http://www.boost.org/LICENSE_1_0.txt
 
-#if defined( __GNUC__ ) && (__GNUC__ >= 7)
+#if defined( __GNUC__ ) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 407)
 #pragma GCC diagnostic ignored "-Wnarrowing"
+#pragma GCC diagnostic ignored "-Wmissing-field-initializers"
 #endif
 
 #ifdef TEST_STD

From a3bef3752cf823917b36dfcf4a9a3316f5435bc2 Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@pdimov.com>
Date: Sun, 16 Jul 2017 01:44:06 +0300
Subject: [PATCH 3/4] Disable failures caused by g++-7 -std=c++17 bug

---
 test/is_list_constructible_test.cpp | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/test/is_list_constructible_test.cpp b/test/is_list_constructible_test.cpp
index 2e7ee62..455da09 100644
--- a/test/is_list_constructible_test.cpp
+++ b/test/is_list_constructible_test.cpp
@@ -72,8 +72,13 @@ BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Y, int const>::value)
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Y, int, int>::value), true);
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Y, int const, int const>::value), true);
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Y, int, int, int>::value), false);
+
+#if defined(CI_SUPPRESS_KNOWN_ISSUES) && defined(__GNUC__) && (__GNUC__ == 7) && (__cplusplus >= 201500)
+// g++ 7.1 in -std=c++1z, c++17 has a bug
+#else
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Y, float>::value), false);
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Y, int, float>::value), false);
+#endif
 
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Z>::value), true);
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Z, int>::value), true);
@@ -81,8 +86,13 @@ BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Z, int const>::value)
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Z, int, int>::value), true);
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Z, int const, int const>::value), true);
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Z, int, int, int>::value), false);
+
+#if defined(CI_SUPPRESS_KNOWN_ISSUES) && defined(__GNUC__) && (__GNUC__ == 7) && (__cplusplus >= 201500)
+// -"-
+#else
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Z, float>::value), false);
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Z, int, float>::value), false);
+#endif
 
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<V>::value), false);
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<V, int>::value), false);

From aa2158f97b309d656533a5087d67559b0afaa2a2 Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@pdimov.com>
Date: Sun, 16 Jul 2017 02:29:40 +0300
Subject: [PATCH 4/4] Define CI_SUPPRESS_KNOWN_ISSUES on Travis, suppress known
 g++-4 issues

---
 .travis.yml                         |  2 +-
 test/is_list_constructible_test.cpp | 20 +++++++++++++++++---
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index f469d33..0764781 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -584,7 +584,7 @@ script:
   - |-
     echo "using $TOOLSET : : $COMPILER : <cxxflags>-std=$CXXSTD ;" > ~/user-config.jam
   - (cd libs/config/test && ../../../b2 config_info_travis_install toolset=$TOOLSET && ./config_info_travis)
-  - ./b2 -j3 libs/type_traits/test toolset=$TOOLSET
+  - ./b2 -j3 libs/type_traits/test toolset=$TOOLSET define=CI_SUPPRESS_KNOWN_ISSUES
 
 notifications:
   email:
diff --git a/test/is_list_constructible_test.cpp b/test/is_list_constructible_test.cpp
index 455da09..bbf1d59 100644
--- a/test/is_list_constructible_test.cpp
+++ b/test/is_list_constructible_test.cpp
@@ -55,7 +55,12 @@ BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<int, int>::value), tr
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<int, int const>::value), true);
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<int, int, int>::value), false);
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<int, char>::value), true);
+
+#if defined(CI_SUPPRESS_KNOWN_ISSUES) && defined(__GNUC__) && (__GNUC__ == 4)
+// g++ 4.x doesn't seem to disallow narrowing
+#else
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<int, float>::value), false);
+#endif
 
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<X>::value), true);
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<X, int>::value), true);
@@ -63,8 +68,13 @@ BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<X, int const>::value)
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<X, int, int>::value), true);
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<X, int const, int const>::value), true);
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<X, int, int, int>::value), false);
+
+#if defined(CI_SUPPRESS_KNOWN_ISSUES) && defined(__GNUC__) && (__GNUC__ == 4)
+// g++ 4.x doesn't seem to disallow narrowing
+#else
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<X, float>::value), false);
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<X, int, float>::value), false);
+#endif
 
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Y>::value), true);
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Y, int>::value), true);
@@ -73,7 +83,9 @@ BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Y, int, int>::value),
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Y, int const, int const>::value), true);
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Y, int, int, int>::value), false);
 
-#if defined(CI_SUPPRESS_KNOWN_ISSUES) && defined(__GNUC__) && (__GNUC__ == 7) && (__cplusplus >= 201500)
+#if defined(CI_SUPPRESS_KNOWN_ISSUES) && defined(__GNUC__) && (__GNUC__ == 4)
+// g++ 4.x doesn't seem to disallow narrowing
+#elif defined(CI_SUPPRESS_KNOWN_ISSUES) && defined(__GNUC__) && (__GNUC__ == 7) && (__cplusplus >= 201500)
 // g++ 7.1 in -std=c++1z, c++17 has a bug
 #else
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Y, float>::value), false);
@@ -87,8 +99,10 @@ BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Z, int, int>::value),
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Z, int const, int const>::value), true);
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Z, int, int, int>::value), false);
 
-#if defined(CI_SUPPRESS_KNOWN_ISSUES) && defined(__GNUC__) && (__GNUC__ == 7) && (__cplusplus >= 201500)
-// -"-
+#if defined(CI_SUPPRESS_KNOWN_ISSUES) && defined(__GNUC__) && (__GNUC__ == 4)
+// g++ 4.x doesn't seem to disallow narrowing
+#elif defined(CI_SUPPRESS_KNOWN_ISSUES) && defined(__GNUC__) && (__GNUC__ == 7) && (__cplusplus >= 201500)
+// g++ 7.1 in -std=c++1z, c++17 has a bug
 #else
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Z, float>::value), false);
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_list_constructible<Z, int, float>::value), false);