Extracting Params of Templated Type

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On Friday, 4 April 2014 at 04:44:56 UTC, Nick Sabalausky wrote:
> If you have a templated type, is there a way to get the 
> compile-time parameters it was instantiated with?
>
> Ie:
>
> ----------------------
> struct Foo(T) {}
>
> alias MyFoo = Foo!int;
> ----------------------
>
> Is there a way to inspect MyFoo to get its T type (in this 
> case, 'int')? *Without* actually making any changes to Foo to 
> explicitly support this?

alias TemplateArgs(T: Foo!U, U) = U;

void main()
{
	assert(is(TemplateArgs!MyFoo == int));
}