Remove unnecessary overloads

doc/system/changes.adoc

@@ -8,6 +8,13 @@ https://www.boost.org/LICENSE_1_0.txt
 # Revision History
 :idprefix:
 
+## Changes in Boost 1.80
+
+* When an `error_code` is converted to `std::error_code` and then back
+  to `error_code`, the original is now restored, if possible.
+* Reworked the conversion from `error_category` to `std::error_category`
+  to avoid the one-time allocation that shows up on leak checkers.
+
 ## Changes in Boost 1.79
 
 * Added a `boost::source_location` parameter to `throw_exception_from_error`.

include/boost/system/detail/error_code.hpp

@@ -144,19 +144,14 @@ public:
         *this = make_error_code( e );
     }
 
-    template<class ErrorCodeEnum> error_code( ErrorCodeEnum e, source_location const * loc,
-        typename detail::enable_if<is_error_code_enum<ErrorCodeEnum>::value>::type* = 0 ) BOOST_NOEXCEPT:
+    error_code( error_code const& ec, source_location const * loc ) BOOST_NOEXCEPT:
         d1_(), lc_flags_( 0 )
     {
-        error_code e2 = make_error_code( e );
+        *this = ec;
 
-        if( e2.lc_flags_ == 0 || e2.lc_flags_ == 1 )
+        if( ec.lc_flags_ != 0 && ec.lc_flags_ != 1 )
         {
-            *this = e2;
-        }
-        else
-        {
-            *this = error_code( e2.d1_.val_, *e2.d1_.cat_, loc );
+            lc_flags_ = ( loc? reinterpret_cast<boost::uintptr_t>( loc ): 2 ) | ( ec.lc_flags_ & 1 );
         }
     }
 
@@ -194,6 +189,11 @@ public:
         *this = error_code( val, cat, loc );
     }
 
+    void assign( error_code const& ec, source_location const * loc ) BOOST_NOEXCEPT
+    {
+        *this = error_code( ec, loc );
+    }
+
     template<typename ErrorCodeEnum>
         BOOST_SYSTEM_CONSTEXPR typename detail::enable_if<is_error_code_enum<ErrorCodeEnum>::value, error_code>::type &
         operator=( ErrorCodeEnum val ) BOOST_NOEXCEPT
@@ -202,13 +202,6 @@ public:
         return *this;
     }
 
-    template<typename ErrorCodeEnum>
-        typename detail::enable_if<is_error_code_enum<ErrorCodeEnum>::value, void>::type
-        assign( ErrorCodeEnum val, source_location const * loc ) BOOST_NOEXCEPT
-    {
-        *this = error_code( val, loc );
-    }
-
     BOOST_SYSTEM_CONSTEXPR void clear() BOOST_NOEXCEPT
     {
         *this = error_code();

test/CMakeLists.txt

@@ -121,6 +121,9 @@ boost_test(TYPE run SOURCES errc_test4.cpp)
 boost_test(TYPE run SOURCES std_interop_test13.cpp)
 boost_test(TYPE run SOURCES std_interop_test14.cpp)
 
+boost_test(TYPE run SOURCES ec_location_test3.cpp)
+boost_test(TYPE run SOURCES ec_location_test4.cpp)
+
 # result
 
 set(BOOST_TEST_COMPILE_FEATURES cxx_std_11)

test/Jamfile.v2

@@ -145,6 +145,9 @@ run errc_test4.cpp ;
 run std_interop_test13.cpp ;
 run std_interop_test14.cpp ;
 
+run ec_location_test3.cpp ;
+run ec_location_test4.cpp ;
+
 # result
 
 import ../../config/checks/config : requires ;

test/ec_location_test3.cpp

@@ -0,0 +1,90 @@
+// Copyright 2021, 2022 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <cerrno>
+
+int main()
+{
+    int const val = ENOENT;
+    boost::system::error_category const & cat = boost::system::generic_category();
+
+    {
+        boost::system::error_code ec;
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        boost::system::error_code ec2( ec, &loc );
+
+        BOOST_TEST_EQ( ec2, ec );
+
+        BOOST_TEST( !ec2.has_location() );
+        BOOST_TEST_EQ( ec2.location(), boost::source_location() );
+
+        boost::system::error_code ec3( ec2, 0 );
+
+        BOOST_TEST_EQ( ec3, ec2 );
+
+        BOOST_TEST( !ec3.has_location() );
+        BOOST_TEST_EQ( ec3.location(), boost::source_location() );
+    }
+
+    {
+        boost::system::error_code ec( val, cat );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        boost::system::error_code ec2( ec, &loc );
+
+        BOOST_TEST_EQ( ec2, ec );
+
+        BOOST_TEST( ec2.has_location() );
+        BOOST_TEST_EQ( ec2.location(), loc );
+
+        boost::system::error_code ec3( ec2, 0 );
+
+        BOOST_TEST_EQ( ec3, ec2 );
+
+        BOOST_TEST( !ec3.has_location() );
+        BOOST_TEST_EQ( ec3.location(), boost::source_location() );
+    }
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+    {
+        std::error_code e2( val, std::generic_category() );
+
+        boost::system::error_code ec( e2 );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        boost::system::error_code ec2( ec, &loc );
+
+        BOOST_TEST_EQ( ec2, ec );
+
+        BOOST_TEST( !ec2.has_location() );
+        BOOST_TEST_EQ( ec2.location(), boost::source_location() );
+
+        boost::system::error_code ec3( ec2, 0 );
+
+        BOOST_TEST_EQ( ec3, ec2 );
+
+        BOOST_TEST( !ec3.has_location() );
+        BOOST_TEST_EQ( ec3.location(), boost::source_location() );
+    }
+
+#endif
+
+    return boost::report_errors();
+}

test/ec_location_test4.cpp

@@ -0,0 +1,93 @@
+// Copyright 2021, 2022 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <cerrno>
+
+int main()
+{
+    int const val = ENOENT;
+    boost::system::error_category const & cat = boost::system::generic_category();
+
+    {
+        boost::system::error_code ec;
+        boost::system::error_code ec2( ec );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        ec.assign( ec, &loc );
+
+        BOOST_TEST_EQ( ec, ec2 );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        ec.assign( ec, 0 );
+
+        BOOST_TEST_EQ( ec, ec2 );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+    }
+
+    {
+        boost::system::error_code ec( val, cat );
+        boost::system::error_code ec2( ec );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        ec.assign( ec, &loc );
+
+        BOOST_TEST_EQ( ec, ec2 );
+
+        BOOST_TEST( ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), loc );
+
+        ec.assign( ec, 0 );
+
+        BOOST_TEST_EQ( ec, ec2 );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+    }
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+    {
+        std::error_code e2( val, std::generic_category() );
+
+        boost::system::error_code ec( e2 );
+        boost::system::error_code ec2( ec );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        ec.assign( ec, &loc );
+
+        BOOST_TEST_EQ( ec, ec2 );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        ec.assign( ec, 0 );
+
+        BOOST_TEST_EQ( ec, ec2 );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+    }
+
+#endif
+
+    return boost::report_errors();
+}