Added documentation comments. Added a policy.

git-svn-id: svn://svn.code.sf.net/p/loki-lib/code/trunk@955 7ec92016-0320-0410-acc4-a06ded1c099a

include/loki/CheckReturn.h

@@ -45,18 +45,20 @@ namespace Loki
 ///  primitive (bool, int, etc...) a pointer, or an enum (such as an error
 ///  condition enum).  It can work with other types that have cheap copy
 ///  operations.
-///
-///  \par OnError Policy
 ///  - OnError is a policy class indicating how to handle the situation when a
 ///  caller does not check or copy the returned value.  Loki provides some
 ///  policy classs and you may also write your own.  For example, you can write
-///  a policy to throw an exception or create a message box when the function
+///  a policy to create a message box when the function ignores the return value.
-///  ignores the return value.  If your write your own, you only need to provide
+///  That would quickly tell you places where code ignores the function call.
-///  a function named "run".
+///  If your write your own, you only need a templated class or struct with a
+///  public function named "run" that accepts a reference to a const value.
 ///
+/// @par Provided Policy Classes
 ///  - IgnoreReturnValue Deliberately ignores when the caller ignores the return value.
 ///  - TriggerAssert Asserts in debug builds if the caller ignores the return value.
 ///  - FprintfStderr Prints out an error message if the caller ignores the return value.
+///  - ThrowTheValue Throws the ignored value as an exception.
+///  - ThrowLogicError Throws a logic_error exception to indicate a programming error.
 ////////////////////////////////////////////////////////////////////////////////
 
 
@@ -69,6 +71,24 @@ struct IgnoreReturnValue
 	}
 };
 
+template<class T>
+struct ThrowTheValue
+{
+	static void run(const T & value )
+	{
+		throw value;
+	}
+};
+
+template<class T>
+struct ThrowLogicError
+{
+	static void run( const T & )
+	{
+		throw ::std::logic_error( "CheckReturn: return value was not checked.\n" );
+	}
+};
+
 template<class T>
 struct TriggerAssert
 {
@@ -83,7 +103,7 @@ struct FprintfStderr
 {
 	static void run(const T&)
 	{
-		fprintf(stderr, "CheckReturn: return value was not checked\n");
+		fprintf(stderr, "CheckReturn: return value was not checked.\n");
 	}
 };