--- /dev/null
+#include <msp/strings/format.h>
+#include "predicate.h"
+
+using namespace std;
+
+namespace Msp {
+namespace GL {
+
+void operator>>(const LexicalConverter &conv, Predicate &pred)
+{
+ const string &str = conv.get();
+ if(str=="NEVER")
+ pred = NEVER;
+ else if(str=="ALWAYS")
+ pred = ALWAYS;
+ else if(str=="LESS")
+ pred = LESS;
+ else if(str=="LEQUAL")
+ pred = LEQUAL;
+ else if(str=="EQUAL")
+ pred = EQUAL;
+ else if(str=="GREATER")
+ pred = GREATER;
+ else if(str=="GEQUAL")
+ pred = GEQUAL;
+ else if(str=="NOTEQUAL")
+ pred = NOTEQUAL;
+ else
+ throw lexical_error(format("conversion of '%s' to Predicate", str));
+}
+
+void operator<<(LexicalConverter &conv, Predicate pred)
+{
+ switch(pred)
+ {
+ case NEVER: conv.result("NEVER"); break;
+ case ALWAYS: conv.result("ALWAYS"); break;
+ case LESS: conv.result("LESS"); break;
+ case LEQUAL: conv.result("LEQUAL"); break;
+ case EQUAL: conv.result("EQUAL"); break;
+ case GREATER: conv.result("GREATER"); break;
+ case GEQUAL: conv.result("GEQUAL"); break;
+ case NOTEQUAL: conv.result("NOTEQUAL"); break;
+ default: conv.result(format("Predicate(%#x)", static_cast<int>(pred))); break;
+ }
+}
+
+} // namespace GL
+} // namespace Msp