Allow for setting of delimiters.

IOStreams/delimiters.h

@@ -27,6 +27,9 @@ namespace Alepha::Hydrogen::IOStreams  ::detail::  delimiters_m
 		explicit
 		Delimiter( const std::string dflt )
 			: state( [dflt] { return dflt; } ) {}
+
+		void set( const std::string s ) { state.setDefault( s ); }
+		void set( const char c ) { set( std::string{ c } ); }
 	};
 
 	namespace exports