MSVC test fix

include/boost/pfr/detail/config.hpp

@@ -49,4 +49,15 @@
 #   endif
 #endif
 
+#if defined(__has_cpp_attribute)
+#   if __has_cpp_attribute(maybe_unused)
+#       define BOOST_PFR_MAYBE_UNUSED [[maybe_unused]]
+#   endif
+#endif
+
+#ifndef BOOST_PFR_MAYBE_UNUSED
+#   define BOOST_PFR_MAYBE_UNUSED
+#endif
+
+
 #endif // BOOST_PFR_DETAIL_CONFIG_HPP

include/boost/pfr/detail/core14_loophole.hpp

@@ -33,6 +33,7 @@
 #include <boost/pfr/detail/make_integer_sequence.hpp>
 #include <boost/pfr/detail/sequence_tuple.hpp>
 #include <boost/pfr/detail/rvalue_t.hpp>
+#include <boost/pfr/detail/unsafe_declval.hpp>
 
 
 #ifdef __clang__
@@ -59,12 +60,6 @@ struct tag {
     friend auto loophole(tag<T,N>);
 };
 
-// For returning non default constructible types. Never used at runtime! GCC's std::declval may not be used in potentionally evaluated contexts, so it does not work here.
-template <class T> constexpr T& unsafe_declval_like() noexcept {
-    T* ptr = nullptr;
-    return *ptr;
-}
-
 // The definitions of friend functions.
 template <class T, class U, std::size_t N, bool B>
 struct fn_def_lref {
@@ -75,13 +70,13 @@ struct fn_def_lref {
         // To workaround the issue, we check that the type U is movable, and move it in that case.
         using no_extents_t = std::remove_all_extents_t<U>;
         return static_cast< std::conditional_t<std::is_move_constructible<no_extents_t>::value, no_extents_t&&, no_extents_t&> >(
-            boost::pfr::detail::unsafe_declval_like<no_extents_t>()
+            boost::pfr::detail::unsafe_declval<no_extents_t&>()
         );
     }
 };
 template <class T, class U, std::size_t N, bool B>
 struct fn_def_rref {
-    friend auto loophole(tag<T,N>) { return std::move(boost::pfr::detail::unsafe_declval_like< std::remove_all_extents_t<U> >()); }
+    friend auto loophole(tag<T,N>) { return std::move(boost::pfr::detail::unsafe_declval< std::remove_all_extents_t<U>& >()); }
 };
 
 
@@ -193,7 +188,7 @@ decltype(auto) tie_or_value(T& val, std::enable_if_t<std::is_enum<std::remove_re
 }
 
 template <class T>
-auto tie_or_value(T& val, std::enable_if_t<std::is_union< std::remove_reference_t<T> >::value>* = 0) noexcept {
+auto tie_or_value(T& /*val*/, std::enable_if_t<std::is_union< std::remove_reference_t<T> >::value>* = 0) noexcept {
     static_assert(
         sizeof(T) && false,
         "====================> Boost.PFR: For safety reasons it is forbidden to reflect unions. See `Reflection of unions` section in the docs for more info."

include/boost/pfr/detail/fields_count.hpp

@@ -10,6 +10,7 @@
 #include <boost/pfr/detail/config.hpp>
 #include <boost/pfr/detail/make_integer_sequence.hpp>
 #include <boost/pfr/detail/size_t_.hpp>
+#include <boost/pfr/detail/unsafe_declval.hpp>
 
 #include <climits>      // CHAR_BIT
 #include <type_traits>
@@ -28,13 +29,15 @@ namespace boost { namespace pfr { namespace detail {
 ///////////////////// Structure that can be converted to reference to anything
 struct ubiq_lref_constructor {
     std::size_t ignore;
-    template <class Type> /*constexpr*/ operator Type&() const noexcept; // Undefined, allows initialization of reference fields (T& and const T&)
+    template <class Type> constexpr operator Type&() const noexcept {  // Allows initialization of reference fields (T& and const T&)
+        return detail::unsafe_declval<Type&>();
+    };
 };
 
 ///////////////////// Structure that can be converted to rvalue reference to anything
 struct ubiq_rref_constructor {
     std::size_t ignore;
-    template <class Type> /*constexpr*/ operator Type&&() const noexcept; // Undefined, allows initialization of rvalue reference fields and move-only types
+    template <class Type> /*constexpr*/ operator Type&&() const noexcept {}; // Allows initialization of rvalue reference fields and move-only types
 };
 
 

include/boost/pfr/detail/unsafe_declval.hpp

@@ -0,0 +1,27 @@
+// Copyright (c) 2019-2020 Antony Polukhin.
+//
+// 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_PFR_DETAIL_UNSAFE_DECLVAL_HPP
+#define BOOST_PFR_DETAIL_UNSAFE_DECLVAL_HPP
+
+#include <boost/pfr/detail/config.hpp>
+
+#include <type_traits>
+
+namespace boost { namespace pfr { namespace detail {
+
+// For returning non default constructible types. Never used at runtime! GCC's
+// std::declval may not be used in potentionally evaluated contexts, so it does not work here.
+template <class T> constexpr T unsafe_declval() noexcept {
+    typename std::remove_reference<T>::type* ptr = 0;
+    ptr += 42; // killing 'null pointer dereference' heuristics of static analysis tools
+    return static_cast<T>(*ptr);
+}
+
+}}} // namespace boost::pfr::detail
+
+
+#endif // BOOST_PFR_DETAIL_UNSAFE_DECLVAL_HPP
+

include/boost/pfr/flat/functions_for.hpp

@@ -54,26 +54,26 @@
 /// std::size_t hash_value(const T& value) noexcept;
 /// \endcode
 
-#define BOOST_PFR_FLAT_FUNCTIONS_FOR(T)                                                                                           \
-    static inline bool operator==(const T& lhs, const T& rhs) noexcept { return ::boost::pfr::flat_equal_to<T>{}(lhs, rhs);      }  \
-    static inline bool operator!=(const T& lhs, const T& rhs) noexcept { return ::boost::pfr::flat_not_equal<T>{}(lhs, rhs);     }  \
-    static inline bool operator< (const T& lhs, const T& rhs) noexcept { return ::boost::pfr::flat_less<T>{}(lhs, rhs);          }  \
-    static inline bool operator> (const T& lhs, const T& rhs) noexcept { return ::boost::pfr::flat_greater<T>{}(lhs, rhs);       }  \
-    static inline bool operator<=(const T& lhs, const T& rhs) noexcept { return ::boost::pfr::flat_less_equal<T>{}(lhs, rhs);    }  \
-    static inline bool operator>=(const T& lhs, const T& rhs) noexcept { return ::boost::pfr::flat_greater_equal<T>{}(lhs, rhs); }  \
-    template <class Char, class Traits>                                                                                             \
-    static ::std::basic_ostream<Char, Traits>& operator<<(::std::basic_ostream<Char, Traits>& out, const T& value) {                \
-        ::boost::pfr::flat_write(out, value);                                                                                       \
-        return out;                                                                                                                 \
-    }                                                                                                                               \
-    template <class Char, class Traits>                                                                                             \
-    static ::std::basic_istream<Char, Traits>& operator>>(::std::basic_istream<Char, Traits>& in, T& value) {                       \
-        ::boost::pfr::flat_read(in, value);                                                                                         \
-        return in;                                                                                                                  \
-    }                                                                                                                               \
-    static inline std::size_t hash_value(const T& v) noexcept {                                                                     \
-        return ::boost::pfr::flat_hash<T>{}(v);                                                                                     \
-    }                                                                                                                               \
+#define BOOST_PFR_FLAT_FUNCTIONS_FOR(T)                                                                                                                    \
+    BOOST_PFR_MAYBE_UNUSED static inline bool operator==(const T& lhs, const T& rhs) noexcept { return ::boost::pfr::flat_equal_to<T>{}(lhs, rhs);      }  \
+    BOOST_PFR_MAYBE_UNUSED static inline bool operator!=(const T& lhs, const T& rhs) noexcept { return ::boost::pfr::flat_not_equal<T>{}(lhs, rhs);     }  \
+    BOOST_PFR_MAYBE_UNUSED static inline bool operator< (const T& lhs, const T& rhs) noexcept { return ::boost::pfr::flat_less<T>{}(lhs, rhs);          }  \
+    BOOST_PFR_MAYBE_UNUSED static inline bool operator> (const T& lhs, const T& rhs) noexcept { return ::boost::pfr::flat_greater<T>{}(lhs, rhs);       }  \
+    BOOST_PFR_MAYBE_UNUSED static inline bool operator<=(const T& lhs, const T& rhs) noexcept { return ::boost::pfr::flat_less_equal<T>{}(lhs, rhs);    }  \
+    BOOST_PFR_MAYBE_UNUSED static inline bool operator>=(const T& lhs, const T& rhs) noexcept { return ::boost::pfr::flat_greater_equal<T>{}(lhs, rhs); }  \
+    template <class Char, class Traits>                                                                                                                    \
+    BOOST_PFR_MAYBE_UNUSED static ::std::basic_ostream<Char, Traits>& operator<<(::std::basic_ostream<Char, Traits>& out, const T& value) {                \
+        ::boost::pfr::flat_write(out, value);                                                                                                              \
+        return out;                                                                                                                                        \
+    }                                                                                                                                                      \
+    template <class Char, class Traits>                                                                                                                    \
+    BOOST_PFR_MAYBE_UNUSED static ::std::basic_istream<Char, Traits>& operator>>(::std::basic_istream<Char, Traits>& in, T& value) {                       \
+        ::boost::pfr::flat_read(in, value);                                                                                                                \
+        return in;                                                                                                                                         \
+    }                                                                                                                                                      \
+    BOOST_PFR_MAYBE_UNUSED static inline std::size_t hash_value(const T& v) noexcept {                                                                     \
+        return ::boost::pfr::flat_hash<T>{}(v);                                                                                                            \
+    }                                                                                                                                                      \
 /**/
 
 #endif // BOOST_PFR_FLAT_FUNCTIONS_FOR_HPP

include/boost/pfr/precise/functions_for.hpp

@@ -52,26 +52,26 @@
 /// std::size_t hash_value(const T& value);
 /// \endcode
 
-#define BOOST_PFR_PRECISE_FUNCTIONS_FOR(T)                                                                              \
-    static inline bool operator==(const T& lhs, const T& rhs) { return ::boost::pfr::equal_to<T>{}(lhs, rhs);      }    \
-    static inline bool operator!=(const T& lhs, const T& rhs) { return ::boost::pfr::not_equal<T>{}(lhs, rhs);     }    \
-    static inline bool operator< (const T& lhs, const T& rhs) { return ::boost::pfr::less<T>{}(lhs, rhs);          }    \
-    static inline bool operator> (const T& lhs, const T& rhs) { return ::boost::pfr::greater<T>{}(lhs, rhs);       }    \
-    static inline bool operator<=(const T& lhs, const T& rhs) { return ::boost::pfr::less_equal<T>{}(lhs, rhs);    }    \
-    static inline bool operator>=(const T& lhs, const T& rhs) { return ::boost::pfr::greater_equal<T>{}(lhs, rhs); }    \
-    template <class Char, class Traits>                                                                                 \
-    static ::std::basic_ostream<Char, Traits>& operator<<(::std::basic_ostream<Char, Traits>& out, const T& value) {    \
-        ::boost::pfr::write(out, value);                                                                                \
-        return out;                                                                                                     \
-    }                                                                                                                   \
-    template <class Char, class Traits>                                                                                 \
-    static ::std::basic_istream<Char, Traits>& operator>>(::std::basic_istream<Char, Traits>& in, T& value) {           \
-        ::boost::pfr::read(in, value);                                                                                  \
-        return in;                                                                                                      \
-    }                                                                                                                   \
-    static inline std::size_t hash_value(const T& v) {                                                                  \
-        return ::boost::pfr::hash<T>{}(v);                                                                              \
-    }                                                                                                                   \
+#define BOOST_PFR_PRECISE_FUNCTIONS_FOR(T)                                                                                                     \
+    BOOST_PFR_MAYBE_UNUSED static inline bool operator==(const T& lhs, const T& rhs) { return ::boost::pfr::equal_to<T>{}(lhs, rhs);      }    \
+    BOOST_PFR_MAYBE_UNUSED static inline bool operator!=(const T& lhs, const T& rhs) { return ::boost::pfr::not_equal<T>{}(lhs, rhs);     }    \
+    BOOST_PFR_MAYBE_UNUSED static inline bool operator< (const T& lhs, const T& rhs) { return ::boost::pfr::less<T>{}(lhs, rhs);          }    \
+    BOOST_PFR_MAYBE_UNUSED static inline bool operator> (const T& lhs, const T& rhs) { return ::boost::pfr::greater<T>{}(lhs, rhs);       }    \
+    BOOST_PFR_MAYBE_UNUSED static inline bool operator<=(const T& lhs, const T& rhs) { return ::boost::pfr::less_equal<T>{}(lhs, rhs);    }    \
+    BOOST_PFR_MAYBE_UNUSED static inline bool operator>=(const T& lhs, const T& rhs) { return ::boost::pfr::greater_equal<T>{}(lhs, rhs); }    \
+    template <class Char, class Traits>                                                                                                        \
+    BOOST_PFR_MAYBE_UNUSED static ::std::basic_ostream<Char, Traits>& operator<<(::std::basic_ostream<Char, Traits>& out, const T& value) {    \
+        ::boost::pfr::write(out, value);                                                                                                       \
+        return out;                                                                                                                            \
+    }                                                                                                                                          \
+    template <class Char, class Traits>                                                                                                        \
+    BOOST_PFR_MAYBE_UNUSED static ::std::basic_istream<Char, Traits>& operator>>(::std::basic_istream<Char, Traits>& in, T& value) {           \
+        ::boost::pfr::read(in, value);                                                                                                         \
+        return in;                                                                                                                             \
+    }                                                                                                                                          \
+    BOOST_PFR_MAYBE_UNUSED static inline std::size_t hash_value(const T& v) {                                                                  \
+        return ::boost::pfr::hash<T>{}(v);                                                                                                     \
+    }                                                                                                                                          \
 /**/
 
 #endif // BOOST_PFR_PRECISE_FUNCTIONS_FOR_HPP

test/Jamfile.v2

@@ -1,4 +1,4 @@
-#  Copyright (C) 2016-2019, Antony Polukhin.
+#  Copyright (C) 2016-2020, Antony Polukhin.
 #
 # Use, modification and distribution is subject to the Boost Software License,
 # Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
@@ -143,6 +143,7 @@ test-suite pfr
     [ run precise/destructuring_tie.cpp             : : : $(CLASSIC_PREC_DEF) : precise_destructuring_tie ]
     [ run precise/error_pfr_c1202.cpp               : : : $(CLASSIC_PREC_DEF) : precise_c1202_issue21 ]
     [ compile-fail precise/non_aggregate.cpp        : $(CLASSIC_PREC_DEF)     : precise_non_aggregate ]
+    [ run precise/tie_anonymous.cpp                 : : : $(CLASSIC_PREC_DEF) [ requires cxx17_structured_bindings ] : precise_tie_anonymous ]
 
     # See "Requirements and Limitations" section of the docs for info on following tests:
     #[ compile-fail precise/template_constructor.cpp   : $(CLASSIC_PREC_DEF) [ requires !cxx17_structured_bindings ] : precise_template_constructor14 ]
@@ -176,6 +177,7 @@ test-suite pfr
     [ run precise/issue30.cpp                       : : : $(LOOPHOLE_PREC_DEF) : precise_lh_issue30 ]
     [ run precise/issue33.cpp                       : : : $(LOOPHOLE_PREC_DEF) : precise_lh_issue33 ]
     [ compile-fail precise/non_aggregate.cpp        : $(LOOPHOLE_PREC_DEF) : precise_lh_non_aggregate ]
+    [ run precise/tie_anonymous.cpp                 : : : $(LOOPHOLE_PREC_DEF) [ requires cxx17_structured_bindings ] : precise_lh_tie_anonymous ]
 
     # See "Requirements and Limitations" section of the docs for info on following tests:
     #[ compile-fail precise/template_constructor.cpp   : $(LOOPHOLE_PREC_DEF) [ requires !cxx17_structured_bindings ] : precise_lh_template_constructor14 ]

test/common/functions_for.cpp

@@ -39,10 +39,11 @@ struct comparable_struct {
 
 BOOST_PFR_TEST_FUNCTIONS_FOR(comparable_struct)
 
-void test_comparable_struct() {
-    comparable_struct s1 {0, 1, false, 6,7,8,9,10,11};
-    comparable_struct s2 = s1;
-    comparable_struct s3 {0, 1, false, 6,7,8,9,10,11111};
+template <typename Struct>
+void test_some_comparable_struct() {
+    Struct s1 {0, 1, false, 6,7,8,9,10,11};
+    Struct s2 = s1;
+    Struct s3 {0, 1, false, 6,7,8,9,10,11111};
     BOOST_TEST_EQ(s1, s2);
     BOOST_TEST(s1 <= s2);
     BOOST_TEST(s1 >= s2);
@@ -56,7 +57,7 @@ void test_comparable_struct() {
 
     std::cout << s1 << std::endl;
 
-    comparable_struct s4;
+    Struct s4;
     std::stringstream ss;
     ss.exceptions ( std::ios::failbit);
     ss << s1;
@@ -67,6 +68,10 @@ void test_comparable_struct() {
     BOOST_TEST_NE(i, j);
 }
 
+void test_comparable_struct() {
+    test_some_comparable_struct<comparable_struct>();
+}
+
 struct empty { operator std::string() { return "empty{}"; } };
 BOOST_PFR_TEST_FUNCTIONS_FOR(empty)
 
@@ -105,12 +110,58 @@ void test_implicit_conversions() {
     BOOST_TEST_EQ(ss.str(), "{}"); // Breaks implicit conversion for types marked with BOOST_PFR_TEST_FUNCTIONS_FOR
 }
 
+namespace {
+
+struct anonymous_comparable_struct {
+    int i; short s; bool bl; int a,b,c,d,e,f;
+};
+
+BOOST_PFR_TEST_FUNCTIONS_FOR(anonymous_comparable_struct)
+
+
+struct other_anonymous_struct {
+    anonymous_comparable_struct a,b;
+};
+
+BOOST_PFR_TEST_FUNCTIONS_FOR(other_anonymous_struct)
+
+}
+
+namespace std {
+template <>
+struct hash<anonymous_comparable_struct> {
+    std::size_t operator()(const anonymous_comparable_struct& val) const noexcept {
+        return hash_value(val);
+    }
+};
+}
+
+namespace {
+
+void test_anonymous_comparable_struct() {
+    test_some_comparable_struct<anonymous_comparable_struct>();
+}
+
+void test_nested_anonymous_comparable_struct() {
+    other_anonymous_struct s1{
+        {0, 1, false, 6,7,8,9,10,11},
+        {0, 1, false, 6,7,8,9,10,11},
+    };
+    auto s2 = s1;
+
+    BOOST_TEST_EQ(s1, s2);
+}
+
+}
+
 int main() {
     test_comparable_struct();
     test_empty_struct();
     test_with_contatiners<std::less<>>();
     test_with_contatiners<std::greater<>>();
     test_implicit_conversions();
+    test_anonymous_comparable_struct();
+    test_nested_anonymous_comparable_struct();
     return boost::report_errors();
 }
 

test/common/non_std_layout.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2018 Antony Polukhin
+// Copyright (c) 2018-2020 Antony Polukhin
 //
 // 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)

test/common/test_tuple_sizes_on.cpp

@@ -122,7 +122,5 @@ void test_counts_on_multiple_chars() {
 
 int main() {
     test_counts_on_multiple_chars< BOOST_PFR_RUN_TEST_ON >();
-
-    return 0;
 }
 

test/precise/get_non_default_constructible.cpp

@@ -11,7 +11,7 @@ struct non_default_constructible {
     T val_;
 
     non_default_constructible() = delete;
-    template <class U> non_default_constructible(U&& v){}
+    template <class U> non_default_constructible(U&& /*v*/){}
 };
 
 struct Foo {

test/precise/optional_like.cpp

@@ -11,7 +11,7 @@ struct optional_like {
     T val_;
 
     optional_like() = default;
-    template <class U> optional_like(U&& v){}
+    template <class U> optional_like(U&& /*v*/){}
 };
 
 struct Foo {

test/precise/tie_anonymous.cpp

@@ -0,0 +1,94 @@
+// Copyright (c) 2020 Antony Polukhin
+//
+// 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/core/lightweight_test.hpp>
+
+#include <boost/pfr/precise/ops.hpp>
+
+#include <string>
+
+#if defined(__has_include)
+#   if __has_include(<optional>)
+#       include <optional>
+#   endif
+#endif
+
+namespace some {
+    struct struct1{ int i; };
+    struct struct2{ int i; };
+}
+
+namespace testing {
+
+namespace {
+
+#ifdef __cpp_lib_optional
+struct anon_with_optional {
+    std::string a;
+    std::optional<some::struct1> b;
+    std::optional<some::struct2> c;
+
+};
+
+struct other_anon_with_optional {
+    std::string a;
+    int b;
+    std::optional<anon_with_optional> c;
+    std::optional<some::struct2> d;
+
+};
+#endif
+
+struct other_anon {
+    int data;
+};
+
+struct anon {
+    other_anon a;
+    other_anon b;
+};
+
+void test_in_anon_ns() {
+    anon x{{1}, {2}};
+    
+    auto v = boost::pfr::structure_tie(x);
+    
+    BOOST_TEST_EQ(std::get<0>(v).data, 1);
+    BOOST_TEST_EQ(std::get<1>(v).data, 2);
+
+#ifdef __cpp_lib_optional
+    other_anon_with_optional opt{"test"};
+    auto opt_val = boost::pfr::structure_tie(opt);
+    BOOST_TEST_EQ(std::get<0>(opt_val), "test");
+#endif
+}
+
+} // anonymous namespace
+
+void test_in_non_non_ns() {
+    anon x{{1}, {2}};
+    
+    auto v = boost::pfr::structure_tie(x);
+    
+    BOOST_TEST_EQ(std::get<0>(v).data, 1);
+    BOOST_TEST_EQ(std::get<1>(v).data, 2);
+
+#ifdef __cpp_lib_optional
+    other_anon_with_optional opt{"test again"};
+    auto opt_val = boost::pfr::structure_tie(opt);
+    BOOST_TEST_EQ(std::get<0>(opt_val), "test again");
+#endif
+}
+
+} // namespace testing
+
+int main() {
+    testing::test_in_anon_ns();
+    testing::test_in_non_non_ns();
+
+    return boost::report_errors();
+}
+
+