Remove path converting constructors from types convertible to path sources.

This causes ambiguities in users' code where the previously added conversion
from user-defined types that have a conversion to one of the path source
types:

  struct my_class
  {
    operator std::string() const;
  };

  std::string to_string(std::string const&);
  std::string to_string(boost::filesystem::path const&);

  to_string(my_class());

The above call is ambiguous as the conversion operator in my_class and
a converting constructor in boost::filesystem::path from my_class are
both available and have equivalent ranks.

Removing the conversion constructors from boost::filesystem::path
means users will have to explicitly cast their types to one of the
path source types before constructing path.

In order to preserve backward compatibility with operator== and operator!=
for paths that also accepted source types (path::string_type,
const path::value_type*), we have to update path::compare and comparison
operators to accept types that are convertible to source types.

Fixes https://github.com/boostorg/filesystem/issues/273.

doc/release_history.html

@@ -39,6 +39,11 @@
     </td>
 </table>
 
+<h2>1.82.0</h2>
+<ul>
+  <li>Fixed compilation errors that could have been caused by <code>path</code> conversion constructors being too permissive on the accepted arguments. (<a href="https://github.com/boostorg/filesystem/issues/273">#273</a>)</li>
+</ul>
+
 <h2>1.81.0</h2>
 <ul>
   <li><b>Deprecated:</b> <code>path</code> construction, assignment and appending from containers of characters, such as <code>std::vector&lt;char&gt;</code> or <code>std::list&lt;wchar_t&gt;</code>, is deprecated in <b>v3</b> and removed in <b>v4</b>. Please use string types or iterators instead.</li>

include/boost/filesystem/detail/path_traits.hpp

@@ -398,37 +398,37 @@ void convert(const wchar_t* from, const wchar_t* from_end, std::string& to, cons
 //  Source dispatch  -----------------------------------------------------------------//
 
 template< typename Source, typename Callback >
-inline void dispatch(Source const& source, Callback cb, const codecvt_type* cvt = NULL);
+typename Callback::result_type dispatch(Source const& source, Callback cb, const codecvt_type* cvt = NULL);
 
 template< typename Callback >
-BOOST_FORCEINLINE void dispatch(const char* source, Callback cb, const codecvt_type* cvt, ntcts_type_tag)
+BOOST_FORCEINLINE typename Callback::result_type dispatch(const char* source, Callback cb, const codecvt_type* cvt, ntcts_type_tag)
 {
-    cb(source, source + std::strlen(source), cvt);
+    return cb(source, source + std::strlen(source), cvt);
 }
 
 template< typename Callback >
-BOOST_FORCEINLINE void dispatch(const wchar_t* source, Callback cb, const codecvt_type* cvt, ntcts_type_tag)
+BOOST_FORCEINLINE typename Callback::result_type dispatch(const wchar_t* source, Callback cb, const codecvt_type* cvt, ntcts_type_tag)
 {
-    cb(source, source + std::wcslen(source), cvt);
+    return cb(source, source + std::wcslen(source), cvt);
 }
 
 template< typename Source, typename Callback >
-BOOST_FORCEINLINE void dispatch(Source const& source, Callback cb, const codecvt_type* cvt, string_class_tag)
+BOOST_FORCEINLINE typename Callback::result_type dispatch(Source const& source, Callback cb, const codecvt_type* cvt, string_class_tag)
 {
-    cb(source.data(), source.data() + source.size(), cvt);
+    return cb(source.data(), source.data() + source.size(), cvt);
 }
 
 template< typename Source, typename Callback >
-BOOST_FORCEINLINE void dispatch(Source const& source, Callback cb, const codecvt_type* cvt, range_type_tag)
+BOOST_FORCEINLINE typename Callback::result_type dispatch(Source const& source, Callback cb, const codecvt_type* cvt, range_type_tag)
 {
     std::basic_string< typename Source::value_type > src(source.begin(), source.end());
-    cb(src.data(), src.data() + src.size(), cvt);
+    return cb(src.data(), src.data() + src.size(), cvt);
 }
 
 #if !defined(BOOST_FILESYSTEM_NO_DEPRECATED) && BOOST_FILESYSTEM_VERSION < 4
 
 template< typename Callback >
-BOOST_FORCEINLINE void dispatch(std::vector< char > const& source, Callback cb, const codecvt_type* cvt, range_type_tag)
+BOOST_FORCEINLINE typename Callback::result_type dispatch(std::vector< char > const& source, Callback cb, const codecvt_type* cvt, range_type_tag)
 {
     const char* data = NULL, *data_end = NULL;
     if (!source.empty())
@@ -436,11 +436,11 @@ BOOST_FORCEINLINE void dispatch(std::vector< char > const& source, Callback cb,
         data = &source[0];
         data_end = data + source.size();
     }
-    cb(data, data_end, cvt);
+    return cb(data, data_end, cvt);
 }
 
 template< typename Callback >
-BOOST_FORCEINLINE void dispatch(std::vector< wchar_t > const& source, Callback cb, const codecvt_type* cvt, range_type_tag)
+BOOST_FORCEINLINE typename Callback::result_type dispatch(std::vector< wchar_t > const& source, Callback cb, const codecvt_type* cvt, range_type_tag)
 {
     const wchar_t* data = NULL, *data_end = NULL;
     if (!source.empty())
@@ -448,19 +448,19 @@ BOOST_FORCEINLINE void dispatch(std::vector< wchar_t > const& source, Callback c
         data = &source[0];
         data_end = data + source.size();
     }
-    cb(data, data_end, cvt);
+    return cb(data, data_end, cvt);
 }
 
 #endif // !defined(BOOST_FILESYSTEM_NO_DEPRECATED) && BOOST_FILESYSTEM_VERSION < 4
 
 // Defined in directory.hpp to avoid circular header dependencies
 template< typename Callback >
-void dispatch(directory_entry const& de, Callback cb, const codecvt_type* cvt, directory_entry_tag);
+typename Callback::result_type dispatch(directory_entry const& de, Callback cb, const codecvt_type* cvt, directory_entry_tag);
 
 template< typename Source, typename Callback >
-BOOST_FORCEINLINE void dispatch(Source const& source, Callback cb, const codecvt_type* cvt)
+BOOST_FORCEINLINE typename Callback::result_type dispatch(Source const& source, Callback cb, const codecvt_type* cvt)
 {
-    path_traits::dispatch(source, cb, cvt,
+    return path_traits::dispatch(source, cb, cvt,
         typename path_traits::path_source_traits< typename boost::remove_cv< Source >::type >::tag_type());
 }
 
@@ -552,35 +552,35 @@ struct make_dependent
 };
 
 template< typename Source, typename Callback >
-BOOST_FORCEINLINE void dispatch_convertible_impl(const char* source, Callback cb, const codecvt_type* cvt)
+BOOST_FORCEINLINE typename Callback::result_type dispatch_convertible_impl(const char* source, Callback cb, const codecvt_type* cvt)
 {
     typedef typename path_traits::make_dependent< const char*, Source >::type source_t;
-    path_traits::dispatch(static_cast< source_t >(source), cb, cvt);
+    return path_traits::dispatch(static_cast< source_t >(source), cb, cvt);
 }
 
 template< typename Source, typename Callback >
-BOOST_FORCEINLINE void dispatch_convertible_impl(const wchar_t* source, Callback cb, const codecvt_type* cvt)
+BOOST_FORCEINLINE typename Callback::result_type dispatch_convertible_impl(const wchar_t* source, Callback cb, const codecvt_type* cvt)
 {
     typedef typename path_traits::make_dependent< const wchar_t*, Source >::type source_t;
-    path_traits::dispatch(static_cast< source_t >(source), cb, cvt);
+    return path_traits::dispatch(static_cast< source_t >(source), cb, cvt);
 }
 
 template< typename Source, typename Callback >
-BOOST_FORCEINLINE void dispatch_convertible_impl(std::string const& source, Callback cb, const codecvt_type* cvt)
+BOOST_FORCEINLINE typename Callback::result_type dispatch_convertible_impl(std::string const& source, Callback cb, const codecvt_type* cvt)
 {
     typedef typename path_traits::make_dependent< std::string, Source >::type source_t;
-    path_traits::dispatch(static_cast< source_t const& >(source), cb, cvt);
+    return path_traits::dispatch(static_cast< source_t const& >(source), cb, cvt);
 }
 
 template< typename Source, typename Callback >
-BOOST_FORCEINLINE void dispatch_convertible_impl(std::wstring const& source, Callback cb, const codecvt_type* cvt)
+BOOST_FORCEINLINE typename Callback::result_type dispatch_convertible_impl(std::wstring const& source, Callback cb, const codecvt_type* cvt)
 {
     typedef typename path_traits::make_dependent< std::wstring, Source >::type source_t;
-    path_traits::dispatch(static_cast< source_t const& >(source), cb, cvt);
+    return path_traits::dispatch(static_cast< source_t const& >(source), cb, cvt);
 }
 
 template< typename Source, typename Callback >
-BOOST_FORCEINLINE void dispatch_convertible_impl
+BOOST_FORCEINLINE typename Callback::result_type dispatch_convertible_impl
 (
     boost::container::basic_string< char, std::char_traits< char >, void > const& source,
     Callback cb,
@@ -588,11 +588,11 @@ BOOST_FORCEINLINE void dispatch_convertible_impl
 )
 {
     typedef typename path_traits::make_dependent< boost::container::basic_string< char, std::char_traits< char >, void >, Source >::type source_t;
-    path_traits::dispatch(static_cast< source_t const& >(source), cb, cvt);
+    return path_traits::dispatch(static_cast< source_t const& >(source), cb, cvt);
 }
 
 template< typename Source, typename Callback >
-BOOST_FORCEINLINE void dispatch_convertible_impl
+BOOST_FORCEINLINE typename Callback::result_type dispatch_convertible_impl
 (
     boost::container::basic_string< wchar_t, std::char_traits< wchar_t >, void > const& source,
     Callback cb,
@@ -600,11 +600,11 @@ BOOST_FORCEINLINE void dispatch_convertible_impl
 )
 {
     typedef typename path_traits::make_dependent< boost::container::basic_string< wchar_t, std::char_traits< wchar_t >, void >, Source >::type source_t;
-    path_traits::dispatch(static_cast< source_t const& >(source), cb, cvt);
+    return path_traits::dispatch(static_cast< source_t const& >(source), cb, cvt);
 }
 
 template< typename Source, typename Callback >
-BOOST_FORCEINLINE void dispatch_convertible_impl
+BOOST_FORCEINLINE typename Callback::result_type dispatch_convertible_impl
 (
     boost::basic_string_view< char, std::char_traits< char > > const& source,
     Callback cb,
@@ -612,11 +612,11 @@ BOOST_FORCEINLINE void dispatch_convertible_impl
 )
 {
     typedef typename path_traits::make_dependent< boost::basic_string_view< char, std::char_traits< char > >, Source >::type source_t;
-    path_traits::dispatch(static_cast< source_t const& >(source), cb, cvt);
+    return path_traits::dispatch(static_cast< source_t const& >(source), cb, cvt);
 }
 
 template< typename Source, typename Callback >
-BOOST_FORCEINLINE void dispatch_convertible_impl
+BOOST_FORCEINLINE typename Callback::result_type dispatch_convertible_impl
 (
     boost::basic_string_view< wchar_t, std::char_traits< wchar_t > > const& source,
     Callback cb,
@@ -624,7 +624,7 @@ BOOST_FORCEINLINE void dispatch_convertible_impl
 )
 {
     typedef typename path_traits::make_dependent< boost::basic_string_view< wchar_t, std::char_traits< wchar_t > >, Source >::type source_t;
-    path_traits::dispatch(static_cast< source_t const& >(source), cb, cvt);
+    return path_traits::dispatch(static_cast< source_t const& >(source), cb, cvt);
 }
 
 #if !defined(BOOST_FILESYSTEM_CXX23_STRING_VIEW_HAS_IMPLICIT_RANGE_CTOR)
@@ -632,60 +632,62 @@ BOOST_FORCEINLINE void dispatch_convertible_impl
 #if !defined(BOOST_NO_CXX17_HDR_STRING_VIEW)
 
 template< typename Source, typename Callback >
-BOOST_FORCEINLINE void dispatch_convertible_impl(std::string_view const& source, Callback cb, const codecvt_type* cvt)
+BOOST_FORCEINLINE typename Callback::result_type dispatch_convertible_impl(std::string_view const& source, Callback cb, const codecvt_type* cvt)
 {
     typedef typename path_traits::make_dependent< std::string_view, Source >::type source_t;
-    path_traits::dispatch(static_cast< source_t const& >(source), cb, cvt);
+    return path_traits::dispatch(static_cast< source_t const& >(source), cb, cvt);
 }
 
 template< typename Source, typename Callback >
-BOOST_FORCEINLINE void dispatch_convertible_impl(std::wstring_view const& source, Callback cb, const codecvt_type* cvt)
+BOOST_FORCEINLINE typename Callback::result_type dispatch_convertible_impl(std::wstring_view const& source, Callback cb, const codecvt_type* cvt)
 {
     typedef typename path_traits::make_dependent< std::wstring_view, Source >::type source_t;
-    path_traits::dispatch(static_cast< source_t const& >(source), cb, cvt);
+    return path_traits::dispatch(static_cast< source_t const& >(source), cb, cvt);
 }
 
 #endif // !defined(BOOST_NO_CXX17_HDR_STRING_VIEW)
 
 template< typename Source, typename Callback >
-BOOST_FORCEINLINE void dispatch_convertible(Source const& source, Callback cb, const codecvt_type* cvt = NULL)
+BOOST_FORCEINLINE typename Callback::result_type dispatch_convertible(Source const& source, Callback cb, const codecvt_type* cvt = NULL)
 {
     typedef typename boost::remove_cv< Source >::type source_t;
-    path_traits::dispatch_convertible_impl< source_t >(source, cb, cvt);
+    return path_traits::dispatch_convertible_impl< source_t >(source, cb, cvt);
 }
 
 #else // !defined(BOOST_FILESYSTEM_CXX23_STRING_VIEW_HAS_IMPLICIT_RANGE_CTOR)
 
 template< typename Source, typename Callback >
-BOOST_FORCEINLINE void dispatch_convertible_sv_impl(std::string_view const& source, Callback cb, const codecvt_type* cvt)
+BOOST_FORCEINLINE typename Callback::result_type dispatch_convertible_sv_impl(std::string_view const& source, Callback cb, const codecvt_type* cvt)
 {
     typedef typename path_traits::make_dependent< std::string_view, Source >::type source_t;
-    path_traits::dispatch(static_cast< source_t const& >(source), cb, cvt);
+    return path_traits::dispatch(static_cast< source_t const& >(source), cb, cvt);
 }
 
 template< typename Source, typename Callback >
-BOOST_FORCEINLINE void dispatch_convertible_sv_impl(std::wstring_view const& source, Callback cb, const codecvt_type* cvt)
+BOOST_FORCEINLINE typename Callback::result_type dispatch_convertible_sv_impl(std::wstring_view const& source, Callback cb, const codecvt_type* cvt)
 {
     typedef typename path_traits::make_dependent< std::wstring_view, Source >::type source_t;
-    path_traits::dispatch(static_cast< source_t const& >(source), cb, cvt);
+    return path_traits::dispatch(static_cast< source_t const& >(source), cb, cvt);
 }
 
 template< typename Source, typename Callback >
 BOOST_FORCEINLINE typename boost::disable_if_c<
-    is_convertible_to_std_string_view< typename boost::remove_cv< Source >::type >::value
+    is_convertible_to_std_string_view< typename boost::remove_cv< Source >::type >::value,
+    typename Callback::result_type
 >::type dispatch_convertible(Source const& source, Callback cb, const codecvt_type* cvt = NULL)
 {
     typedef typename boost::remove_cv< Source >::type source_t;
-    path_traits::dispatch_convertible_impl< source_t >(source, cb, cvt);
+    return path_traits::dispatch_convertible_impl< source_t >(source, cb, cvt);
 }
 
 template< typename Source, typename Callback >
 BOOST_FORCEINLINE typename boost::enable_if_c<
-    is_convertible_to_std_string_view< typename boost::remove_cv< Source >::type >::value
+    is_convertible_to_std_string_view< typename boost::remove_cv< Source >::type >::value,
+    typename Callback::result_type
 >::type dispatch_convertible(Source const& source, Callback cb, const codecvt_type* cvt = NULL)
 {
     typedef typename boost::remove_cv< Source >::type source_t;
-    path_traits::dispatch_convertible_sv_impl< source_t >(source, cb, cvt);
+    return path_traits::dispatch_convertible_sv_impl< source_t >(source, cb, cvt);
 }
 
 #endif // !defined(BOOST_FILESYSTEM_CXX23_STRING_VIEW_HAS_IMPLICIT_RANGE_CTOR)

include/boost/filesystem/directory.hpp

@@ -174,10 +174,10 @@ namespace path_traits {
 
 // Dispatch function for integration with path class
 template< typename Callback >
-BOOST_FORCEINLINE void dispatch(directory_entry const& de, Callback cb, const codecvt_type* cvt, directory_entry_tag)
+BOOST_FORCEINLINE typename Callback::result_type dispatch(directory_entry const& de, Callback cb, const codecvt_type* cvt, directory_entry_tag)
 {
     boost::filesystem::path::string_type const& source = de.path().native();
-    cb(source.data(), source.data() + source.size(), cvt);
+    return cb(source.data(), source.data() + source.size(), cvt);
 }
 
 } // namespace path_traits

include/boost/filesystem/path.hpp

@@ -227,6 +227,35 @@ private:
         }
     };
 
+    //! Path comparison operation
+    class compare_op;
+    friend class compare_op;
+    class compare_op
+    {
+    private:
+        path const& m_self;
+
+    public:
+        typedef int result_type;
+
+        explicit compare_op(path const& self) BOOST_NOEXCEPT : m_self(self) {}
+
+        BOOST_FORCEINLINE result_type operator() (const value_type* source, const value_type* source_end, const codecvt_type* = NULL) const
+        {
+            return m_self.compare(path(source, source_end));
+        }
+
+        template< typename OtherChar >
+        BOOST_FORCEINLINE result_type operator() (const OtherChar* source, const OtherChar* source_end, const codecvt_type* cvt = NULL) const
+        {
+            path src;
+            detail::path_traits::convert(source, source_end, src.m_pathname, cvt);
+            return m_self.compare(src);
+        }
+    };
+
+    struct sfinae_helper;
+
 public:
     class iterator;
     friend class iterator;
@@ -255,10 +284,7 @@ public:
         typename Source,
         typename = typename boost::enable_if_c<
             boost::conjunction<
-                boost::disjunction<
                 detail::path_traits::is_path_source< typename boost::remove_cv< Source >::type >,
-                    detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >
-                >,
                 boost::negation< detail::path_traits::is_native_path_source< typename boost::remove_cv< Source >::type > >
             >::value
         >::type
@@ -268,10 +294,7 @@ public:
     template< typename Source >
     path(Source const& source, typename boost::enable_if_c<
         boost::conjunction<
-            boost::disjunction<
             detail::path_traits::is_path_source< typename boost::remove_cv< Source >::type >,
-                detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >
-            >,
             boost::negation< detail::path_traits::is_native_path_source< typename boost::remove_cv< Source >::type > >
         >::value
     >::type* = NULL)
@@ -285,23 +308,17 @@ public:
         typename Source,
         typename = typename boost::enable_if_c<
             boost::conjunction<
-                boost::disjunction<
                 detail::path_traits::is_path_source< typename boost::remove_cv< Source >::type >,
-                    detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >
-                >,
                 boost::negation< detail::path_traits::is_native_path_source< typename boost::remove_cv< Source >::type > >
             >::value
         >::type
     >
-    path(Source const& source, codecvt_type const& cvt)
+    explicit path(Source const& source, codecvt_type const& cvt)
 #else
     template< typename Source >
-    path(Source const& source, codecvt_type const& cvt, typename boost::enable_if_c<
+    explicit path(Source const& source, codecvt_type const& cvt, typename boost::enable_if_c<
         boost::conjunction<
-            boost::disjunction<
             detail::path_traits::is_path_source< typename boost::remove_cv< Source >::type >,
-                detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >
-            >,
             boost::negation< detail::path_traits::is_native_path_source< typename boost::remove_cv< Source >::type > >
         >::value
     >::type* = NULL)
@@ -568,10 +585,7 @@ public:
 
     template< typename Source >
     typename boost::enable_if_c<
-        boost::disjunction<
+        detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >::value,
-            detail::path_traits::is_path_source< typename boost::remove_cv< Source >::type >,
-            detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >
-        >::value,
         path&
     >::type operator+=(Source const& source)
     {
@@ -710,10 +724,7 @@ public:
 
     template< typename Source >
     BOOST_FORCEINLINE typename boost::enable_if_c<
-        boost::disjunction<
+        detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >::value,
-            detail::path_traits::is_path_source< typename boost::remove_cv< Source >::type >,
-            detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >
-        >::value,
         path&
     >::type operator/=(Source const& source)
     {
@@ -947,6 +958,48 @@ public:
         return BOOST_FILESYSTEM_VERSIONED_SYM(compare)(p);
     }
 
+    template< typename Source >
+    BOOST_FORCEINLINE typename boost::enable_if_c<
+        detail::path_traits::is_path_source< typename boost::remove_cv< Source >::type >::value,
+        int
+    >::type compare(Source const& source) const
+    {
+        return detail::path_traits::dispatch(source, compare_op(*this));
+    }
+
+    template< typename Source >
+    BOOST_FORCEINLINE typename boost::enable_if_c<
+        boost::conjunction<
+            detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >,
+            boost::negation< detail::path_traits::is_path_source< typename boost::remove_cv< Source >::type > >
+        >::value,
+        int
+    >::type compare(Source const& source) const
+    {
+        return detail::path_traits::dispatch_convertible(source, compare_op(*this));
+    }
+
+    template< typename Source >
+    BOOST_FORCEINLINE typename boost::enable_if_c<
+        detail::path_traits::is_path_source< typename boost::remove_cv< Source >::type >::value,
+        int
+    >::type compare(Source const& source, codecvt_type const& cvt) const
+    {
+        return detail::path_traits::dispatch(source, compare_op(*this), &cvt);
+    }
+
+    template< typename Source >
+    BOOST_FORCEINLINE typename boost::enable_if_c<
+        boost::conjunction<
+            detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >,
+            boost::negation< detail::path_traits::is_path_source< typename boost::remove_cv< Source >::type > >
+        >::value,
+        int
+    >::type compare(Source const& source, codecvt_type const& cvt) const
+    {
+        return detail::path_traits::dispatch_convertible(source, compare_op(*this), &cvt);
+    }
+
     //  -----  decomposition  -----
 
     path root_path() const { return path(m_pathname.c_str(), m_pathname.c_str() + find_root_path_size()); }
@@ -1239,31 +1292,140 @@ BOOST_FORCEINLINE bool operator==(path const& lhs, path const& rhs)
     return lhs.compare(rhs) == 0;
 }
 
+template< typename Source >
+BOOST_FORCEINLINE typename boost::enable_if_c<
+    detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >::value,
+    bool
+>::type operator==(path const& lhs, Source const& rhs)
+{
+    return lhs.compare(rhs) == 0;
+}
+
+template< typename Source >
+BOOST_FORCEINLINE typename boost::enable_if_c<
+    detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >::value,
+    bool
+>::type operator==(Source const& lhs, path const& rhs)
+{
+    return rhs.compare(lhs) == 0;
+}
+
 BOOST_FORCEINLINE bool operator!=(path const& lhs, path const& rhs)
 {
     return lhs.compare(rhs) != 0;
 }
 
+template< typename Source >
+BOOST_FORCEINLINE typename boost::enable_if_c<
+    detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >::value,
+    bool
+>::type operator!=(path const& lhs, Source const& rhs)
+{
+    return lhs.compare(rhs) != 0;
+}
+
+template< typename Source >
+BOOST_FORCEINLINE typename boost::enable_if_c<
+    detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >::value,
+    bool
+>::type operator!=(Source const& lhs, path const& rhs)
+{
+    return rhs.compare(lhs) != 0;
+}
+
 BOOST_FORCEINLINE bool operator<(path const& lhs, path const& rhs)
 {
     return lhs.compare(rhs) < 0;
 }
 
+template< typename Source >
+BOOST_FORCEINLINE typename boost::enable_if_c<
+    detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >::value,
+    bool
+>::type operator<(path const& lhs, Source const& rhs)
+{
+    return lhs.compare(rhs) < 0;
+}
+
+template< typename Source >
+BOOST_FORCEINLINE typename boost::enable_if_c<
+    detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >::value,
+    bool
+>::type operator<(Source const& lhs, path const& rhs)
+{
+    return rhs.compare(lhs) > 0;
+}
+
 BOOST_FORCEINLINE bool operator<=(path const& lhs, path const& rhs)
 {
-    return !(rhs < lhs);
+    return lhs.compare(rhs) <= 0;
+}
+
+template< typename Source >
+BOOST_FORCEINLINE typename boost::enable_if_c<
+    detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >::value,
+    bool
+>::type operator<=(path const& lhs, Source const& rhs)
+{
+    return lhs.compare(rhs) <= 0;
+}
+
+template< typename Source >
+BOOST_FORCEINLINE typename boost::enable_if_c<
+    detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >::value,
+    bool
+>::type operator<=(Source const& lhs, path const& rhs)
+{
+    return rhs.compare(lhs) >= 0;
 }
 
 BOOST_FORCEINLINE bool operator>(path const& lhs, path const& rhs)
 {
-    return rhs < lhs;
+    return lhs.compare(rhs) > 0;
+}
+
+template< typename Source >
+BOOST_FORCEINLINE typename boost::enable_if_c<
+    detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >::value,
+    bool
+>::type operator>(path const& lhs, Source const& rhs)
+{
+    return lhs.compare(rhs) > 0;
+}
+
+template< typename Source >
+BOOST_FORCEINLINE typename boost::enable_if_c<
+    detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >::value,
+    bool
+>::type operator>(Source const& lhs, path const& rhs)
+{
+    return rhs.compare(lhs) < 0;
 }
 
 BOOST_FORCEINLINE bool operator>=(path const& lhs, path const& rhs)
 {
-    return !(lhs < rhs);
+    return lhs.compare(rhs) >= 0;
 }
 
+template< typename Source >
+BOOST_FORCEINLINE typename boost::enable_if_c<
+    detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >::value,
+    bool
+>::type operator>=(path const& lhs, Source const& rhs)
+{
+    return lhs.compare(rhs) >= 0;
+}
+
+template< typename Source >
+BOOST_FORCEINLINE typename boost::enable_if_c<
+    detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >::value,
+    bool
+>::type operator>=(Source const& lhs, path const& rhs)
+{
+    return rhs.compare(lhs) <= 0;
+}
+
+
 // Note: Declared as a template to delay binding to Boost.ContainerHash functions and make the dependency optional
 template< typename T >
 inline typename boost::enable_if_c<
@@ -1294,10 +1456,7 @@ BOOST_FORCEINLINE path operator/(path lhs, path const& rhs)
 
 template< typename Source >
 BOOST_FORCEINLINE typename boost::enable_if_c<
-    boost::disjunction<
+    detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >::value,
-        detail::path_traits::is_path_source< typename boost::remove_cv< Source >::type >,
-        detail::path_traits::is_convertible_to_path_source< typename boost::remove_cv< Source >::type >
-    >::value,
     path
 >::type operator/(path lhs, Source const& rhs)
 {

test/path_test.cpp

@@ -187,6 +187,15 @@ typedef basic_custom_string< char > custom_string;
 typedef basic_custom_string< wchar_t > wcustom_string;
 typedef basic_custom_string< fs::path::value_type > pcustom_string;
 
+inline std::string const& to_string(std::string const& s)
+{
+    return s;
+}
+
+inline std::string to_string(fs::path const& p)
+{
+    return p.string();
+}
 
 std::string platform(BOOST_PLATFORM);
 
@@ -2102,6 +2111,11 @@ void construction_tests()
 #if !defined(BOOST_NO_CXX17_HDR_STRING_VIEW)
     PATH_TEST_EQ(std::string_view("foo"), "foo");
 #endif
+
+    // Check that path constructors don't cause ambiguity for to_string calls
+    // https://github.com/boostorg/filesystem/issues/273
+    custom_string c("test");
+    BOOST_TEST_EQ(to_string(c), std::string("test"));
 }
 
 //  append_tests  --------------------------------------------------------------------//