Remove some warnings

Update libcifpp dependency

CMakeLists.txt

@@ -25,7 +25,7 @@
 cmake_minimum_required(VERSION 3.16)
 
 # set the project name
-project(libpdb-redo VERSION 3.1.2 LANGUAGES CXX C)
+project(libpdb-redo VERSION 3.1.3 LANGUAGES CXX C)
 
 list(APPEND CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake")
 
@@ -114,7 +114,7 @@ endif()
 
 if(NOT PDB_REDO_META)
 	find_package(newuoa REQUIRED)
-	find_package(cifpp 5.0.8 REQUIRED)
+	find_package(cifpp 7.0.6 REQUIRED)
 endif()
 
 # Create a revision file, containing the current git version info

src/AtomShape.cpp

@@ -474,7 +474,7 @@ struct AtomShapeImpl
 		mYi = 0;
 		mFst = std::vector<double>(st.size(), 0);
 
-		auto &D =
+		auto D =
 			mElectronScattering ? atom_type_traits(symbol).elsf() : atom_type_traits(symbol).wksf(charge);
 		auto bIso = clipper::Util::u2b(uIso);
 
@@ -551,7 +551,7 @@ struct AtomShapeAnisoImpl : public AtomShapeImpl
 		: AtomShapeImpl(location, symbol, charge, static_cast<float>(anisou.u_iso()), occupancy, resHigh, resLow, electronScattering)
 		, mAnisoU(anisou)
 	{
-		auto &D =
+		auto D =
 			mElectronScattering ? atom_type_traits(symbol).elsf() : atom_type_traits(symbol).wksf(charge);
 
 		const float fourpi2 = static_cast<float>(4 * kPI * kPI);

src/DistanceMap.cpp

@@ -353,7 +353,8 @@ std::vector<cif::mm::atom> DistanceMap::near(const cif::mm::atom &atom, float ma
 
 	std::vector<cif::mm::atom> result;
 
-	auto &atom_site = atom.get_row().get_category();
+	auto rh = atom.get_row();
+	auto &atom_site = rh.get_category();
 
 	for (size_t i = mIA[ixa]; i < mIA[ixa + 1]; ++i)
 	{