March 22, 2013
void main(){
	import std.demangle;
	import std.stdio;
	writeln(demangle("_D5tango4text7convert6Format12__ModuleInfoZ"));
//_D5tango4text7convert6Format12__ModuleInfoZ
	writeln(demangle("_D5tango4text7Unicode6toFoldFAxaAaZAa"));
//char[] tango.text.Unicode.toFold(const(char)[], char[])
}
March 23, 2013
On Friday, 22 March 2013 at 11:23:30 UTC, timotheecour wrote:
> void main(){
> 	import std.demangle;
> 	import std.stdio;
> 	writeln(demangle("_D5tango4text7convert6Format12__ModuleInfoZ"));
> //_D5tango4text7convert6Format12__ModuleInfoZ
> 	writeln(demangle("_D5tango4text7Unicode6toFoldFAxaAaZAa"));
> //char[] tango.text.Unicode.toFold(const(char)[], char[])
> }

Last time I tried to use demangle it didn't work on types, only functions. Your first symbol is a type, so looks like the same problem.