Changed classes inherited from std::string from is-a to has-a std::string.

* Removed std::string base class for SDAI_String and SDAI_Binary.
* Added necessary std::string interface functions to SDAI_String and SDAI_Binary.
* Removed msvc specific code from sdaiString.h

src/cldai/sdaiBinary.cc

@@ -12,11 +12,34 @@
 #include <sstream>
 #include <sdai.h>
 
+SDAI_Binary::SDAI_Binary( const char * str, int max ) {
+	content = std::string( str, max );
+}
+
+SDAI_Binary::SDAI_Binary( const std::string & s ) {
+	content = std::string( s );
+}
+
+SDAI_Binary::~SDAI_Binary( void ) {
+}
+
 SDAI_Binary & SDAI_Binary::operator= ( const char * s ) {
-    std::string::operator= ( s );
+    content = std::string( s );
     return *this;
 }
 
+void SDAI_Binary::clear( void ) {
+	content.clear();
+}
+
+bool SDAI_Binary::empty( void ) const {
+	return content.empty();
+}
+
+const char * SDAI_Binary::c_str( void ) const {
+	return content.c_str();
+}
+
 void SDAI_Binary::STEPwrite( ostream & out ) const {
     const char * str = 0;
     if( empty() ) {

src/cldai/sdaiBinary.h

@@ -14,21 +14,22 @@
 * and is not subject to copyright.
 */
 
-class SCL_DAI_EXPORT SDAI_Binary : public std::string {
-    public:
+class SCL_DAI_EXPORT SDAI_Binary {
+	private:
+		std::string content;
+	public:
 
         //constructor(s) & destructor
-        SDAI_Binary( const char * str = 0, int max = 0 )
-            : std::string( str, max ) { }
-
-        SDAI_Binary( const std::string & s )   : std::string( s ) { }
-
-
-        ~SDAI_Binary()  {  }
+        SDAI_Binary( const char * str = 0, int max = 0 );
+        SDAI_Binary( const std::string & s );
+        ~SDAI_Binary( void );
 
         //  operators
         SDAI_Binary & operator= ( const char * s );
 
+		void clear( void );
+		bool empty( void ) const;
+		const char * c_str( void ) const;
         // format for STEP
         const char * asStr() const  {
             return c_str();

src/cldai/sdaiString.cc

@@ -12,11 +12,43 @@
 #include <sdai.h>
 #include <sstream>
 
+SDAI_String::SDAI_String( const char * str, int max ) {
+	content = std::string( str, max );
+}
+
+SDAI_String::SDAI_String( const std::string & s ) {
+	content = std::string( s );
+}
+
+SDAI_String::SDAI_String( const SDAI_String & s ) {
+	content = std::string( s.c_str() );
+}
+
+SDAI_String::~SDAI_String( void ) {
+}
+
 SDAI_String & SDAI_String::operator= ( const char * s ) {
-    std::string::operator= ( s );
+	content = std::string( s );
     return *this;
 }
 
+bool SDAI_String::operator== ( const char * s ) const {
+	return ( content == s );
+}
+
+void SDAI_String::clear( void ) {
+	content.clear();
+}
+
+bool SDAI_String::empty( void ) const {
+	return content.empty();
+}
+
+const char * SDAI_String::c_str( void ) const {
+	return content.c_str();
+}
+
+
 void SDAI_String::STEPwrite( ostream & out ) const {
     out << c_str();
 }
@@ -46,7 +78,7 @@ Severity SDAI_String::STEPread( istream & in, ErrorDescriptor * err ) {
 
     // extract the string from the inputstream
     string s = ToExpressStr( in, err );
-    operator+= ( s );
+    content += s;
 
     // retrieve current severity
     Severity sev = err -> severity();

src/cldai/sdaiString.h

@@ -13,27 +13,24 @@
 
 #include <scl_export.h>
 
-/* 
-* In MSVC2010 std::string::npos is no longer exported from it's libraries.
-* This might be a bug but following code make sure the member is known
-* and fixes the linker issue for this symbol.
-*/
-#if defined(__MSVC__) && _MSC_VER == 1600 /* MSVC2010 version */
-const std::string::size_type std::string::npos = size_t(-1); 
-#endif
-
-class SCL_DAI_EXPORT SDAI_String : public std::string {
+class SCL_DAI_EXPORT SDAI_String {
+	private:
+		std::string content;
     public:
 
         //constructor(s) & destructor
-        SDAI_String( const char * str = 0, int max = 0 ) : std::string( str, max ) { }
-        SDAI_String( const std::string & s )   : std::string( s ) { }
-        SDAI_String( const SDAI_String & s )  : std::string( s ) { }
-        ~SDAI_String() { }
+        SDAI_String( const char * str = 0, int max = 0 );
+        SDAI_String( const std::string & s );
+        SDAI_String( const SDAI_String & s );
+        ~SDAI_String( void );
 
 //  operators
         SDAI_String & operator= ( const char * s );
-
+		bool operator== ( const char * s ) const;
+		
+		void clear( void );
+		bool empty( void ) const;
+		const char * c_str( void ) const;
         // format for STEP
         const char * asStr( std::string & s ) const {
             return s.c_str();

src/clstepcore/read_func.cc

@@ -560,7 +560,7 @@ Severity FindStartOfInstance( istream & in, std::string & inst ) {
             case '\'':  // get past the string
                 in.putback( c );
                 tmp.STEPread( in, &errs );
-                inst.append( tmp );
+                inst.append( tmp.c_str() );
                 break;
 
             case '\0':  // problem in input ?
@@ -591,7 +591,7 @@ Severity SkipInstance( istream & in, std::string & inst ) {
             case '\'':  // get past the string
                 in.putback( c );
                 tmp.STEPread( in, &errs );
-                inst.append( tmp );
+                inst.append( tmp.c_str() );
 
                 break;
 

src/clutils/errordesc.cc

@@ -130,8 +130,9 @@ ErrorDescriptor::ErrorDescriptor( Severity s,  DebugLevel d ) : _severity( s ) {
     if( d  != DEBUG_OFF ) {
         _debug_level = d;
     }
-    _userMsg.clear();
-    _detailMsg.clear();
+}
+
+ErrorDescriptor::~ErrorDescriptor( void ) {
 }
 
 void ErrorDescriptor::UserMsg( const char * msg ) {

src/clutils/errordesc.h

@@ -57,16 +57,17 @@ enum  DebugLevel  {
  ******************************************************************/
 
 class SCL_UTILS_EXPORT ErrorDescriptor {
-    protected:
+	private:
+		std::string _userMsg, _detailMsg;
+	protected:
         Severity    _severity;
 
         static DebugLevel    _debug_level;
         static ostream * _out; // note this will not be persistent
-
-        std::string _userMsg, _detailMsg;
     public:
         ErrorDescriptor( Severity s    = SEVERITY_NULL,
                          DebugLevel d  = DEBUG_OFF );
+		~ErrorDescriptor( void );
 
         void PrintContents( ostream & out = cout ) const;