Member predicate Declaration::getTemplateArgumentKind

Gets the template argument value at index index used to instantiate this declaration from a template. When called on a template, this will return the template parameter value at index index if it exists.

For example:

template<typename T, T X> class Foo;

Will have getTemplateArgumentKind(1) return T, and no result for getTemplateArgumentKind(0).

`Foo<int, 10> bar;

Will have getTemplateArgumentKind(1) return int, and no result for getTemplateArgumentKind(0).