matchArg refactoring

Author: danmar

lib/suppressions.cpp

@@ -669,10 +669,10 @@ polyspace::Parser::Parser(const Settings &settings)
         if (pos == std::string::npos)
             return false;
 
-        if (pos > 0 && args[pos - 1] != ' ')
-            return false;
+        const char prevChar = (pos > 0) ? args[pos - 1] : ' ';
+        const char nextChar = (pos + arg.size() < args.size()) ? args[pos + arg.size()] : ' ';
 
-        return pos == args.size() - arg.size() || args[pos + arg.size()] == ' ';
+        return prevChar == ' ' && (nextChar == ' ' || nextChar == ':');
     };
 
     if (matchArg("--misra-c-2012")) {