Enable more C++ compiler warnings

solc/CommandLineInterface.cpp

@@ -92,6 +92,9 @@ namespace solidity::frontend
 
 bool g_hasOutput = false;
 
+namespace
+{
+
 std::ostream& sout()
 {
 	g_hasOutput = true;
@@ -105,6 +108,8 @@ std::ostream& serr(bool _used = true)
 	return cerr;
 }
 
+}
+
 #define cout
 #define cerr
 
@@ -329,6 +334,9 @@ static bool needsHumanTargetedStdout(po::variables_map const& _args)
 	return false;
 }
 
+namespace
+{
+
 bool checkMutuallyExclusive(boost::program_options::variables_map const& args, std::string const& _optionA, std::string const& _optionB)
 {
 	if (args.count(_optionA) && args.count(_optionB))
@@ -340,6 +348,8 @@ bool checkMutuallyExclusive(boost::program_options::variables_map const& args, s
 	return true;
 }
 
+}
+
 void CommandLineInterface::handleBinary(string const& _contract)
 {
 	if (m_args.count(g_argBinary))