Avoid -Wsign-conversion warning

.github/workflows/ci.yml

@@ -167,7 +167,7 @@ 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
@@ -193,7 +193,7 @@ 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
 

include/boost/smart_ptr/detail/sp_counted_base_gcc_atomic.hpp

@@ -137,7 +137,7 @@ public:
 
     long use_count() const // nothrow
     {
-        return atomic_load( &use_count_ );
+        return static_cast<long>( atomic_load( &use_count_ ) );
     }
 };