Support fn.contains(f) where f is a function. Fixes #46.

.github/workflows/ci.yml

@@ -65,6 +65,12 @@ jobs:
             os: ubuntu-22.04
             install: g++-12-multilib
             address-model: 32,64
+          - toolset: gcc-13
+            cxxstd: "03,11,14,17,20,2b"
+            os: ubuntu-latest
+            container: ubuntu:23.04
+            install: g++-13-multilib
+            address-model: 32,64
           - toolset: clang
             compiler: clang++-3.9
             cxxstd: "03,11,14"
@@ -130,6 +136,12 @@ jobs:
             cxxstd: "03,11,14,17,20,2b"
             os: ubuntu-22.04
             install: clang-15
+          - toolset: clang
+            compiler: clang++-16
+            cxxstd: "03,11,14,17,20,2b"
+            os: ubuntu-latest
+            container: ubuntu:23.04
+            install: clang-16
           - toolset: clang
             cxxstd: "03,11,14,17,2a"
             os: macos-11
@@ -154,7 +166,7 @@ jobs:
         if: matrix.container
         run: |
           apt-get update
-          apt-get -y install sudo python git g++
+          apt-get -y install sudo python3 git g++
 
       - name: Install packages
         if: matrix.install
@@ -180,7 +192,7 @@ jobs:
           cd boost-root
           cp -r $GITHUB_WORKSPACE/* libs/$LIBRARY
           git submodule update --init tools/boostdep
-          python tools/boostdep/depinst/depinst.py --git_args "--jobs 3" $LIBRARY
+          python3 tools/boostdep/depinst/depinst.py --git_args "--jobs 3" $LIBRARY
           ./bootstrap.sh
           ./b2 -d0 headers
 
@@ -263,6 +275,7 @@ jobs:
           - os: ubuntu-22.04
           - os: macos-11
           - os: macos-12
+          - os: macos-13
 
     runs-on: ${{matrix.os}}
 
@@ -310,6 +323,7 @@ jobs:
           - os: ubuntu-22.04
           - os: macos-11
           - os: macos-12
+          - os: macos-13
 
     runs-on: ${{matrix.os}}
 
@@ -367,6 +381,7 @@ jobs:
           - os: ubuntu-22.04
           - os: macos-11
           - os: macos-12
+          - os: macos-13
 
     runs-on: ${{matrix.os}}
 

include/boost/function/function_base.hpp

@@ -25,6 +25,7 @@
 #include <boost/type_traits/alignment_of.hpp>
 #include <boost/type_traits/enable_if.hpp>
 #include <boost/type_traits/integral_constant.hpp>
+#include <boost/type_traits/is_function.hpp>
 #include <boost/assert.hpp>
 #include <boost/config.hpp>
 #include <boost/config/workaround.hpp>
@@ -652,7 +653,8 @@ public:
     }
 
   template<typename F>
-    bool contains(const F& f) const
+    typename boost::enable_if_< !boost::is_function<F>::value, bool >::type
+	contains(const F& f) const
     {
       if (const F* fp = this->template target<F>())
       {
@@ -662,6 +664,19 @@ public:
       }
     }
 
+  template<typename Fn>
+    typename boost::enable_if_< boost::is_function<Fn>::value, bool >::type
+	contains(Fn& f) const
+    {
+      typedef Fn* F;
+      if (const F* fp = this->template target<F>())
+      {
+        return function_equal(*fp, &f);
+      } else {
+        return false;
+      }
+    }
+
 #if defined(__GNUC__) && __GNUC__ == 3 && __GNUC_MINOR__ <= 3
   // GCC 3.3 and newer cannot copy with the global operator==, due to
   // problems with instantiation of function return types before it

test/Jamfile.v2

@@ -90,3 +90,6 @@ run fn_eq_bind_test.cpp ;
 # /usr/include/c++/4.4/bits/shared_ptr.h:146: error: cannot use typeid with -fno-rtti
 run contains_test.cpp : : : <rtti>off <toolset>gcc-4.4,<cxxstd>0x:<build>no : contains_test_no_rtti ;
 run contains2_test.cpp : : : <rtti>off <toolset>gcc-4.4,<cxxstd>0x:<build>no : contains2_test_no_rtti ;
+
+run contains3_test.cpp ;
+run contains3_test.cpp : : : <rtti>off <toolset>gcc-4.4,<cxxstd>0x:<build>no : contains3_test_no_rtti ;

test/contains3_test.cpp

@@ -0,0 +1,33 @@
+// Copyright 2023 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/function.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+static int f()
+{
+    return 1;
+}
+
+static int g()
+{
+    return 2;
+}
+
+int main()
+{
+    {
+        boost::function<int()> fn;
+        BOOST_TEST( !fn.contains( f ) );
+        BOOST_TEST( !fn.contains( g ) );
+    }
+
+    {
+        boost::function<int()> fn( f );
+        BOOST_TEST( fn.contains( f ) );
+        BOOST_TEST( !fn.contains( g ) );
+    }
+
+    return boost::report_errors();
+}